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Arthroscopic Single-Bundle Anterior Cruciate Ligament Reconstruction With Periosteum-Enveloping Hamstring Tendon Graft: Clinical Outcome at 2 to 7 Years
Arthroscopic Single-Bundle Anterior Cruciate Ligament Reconstruction With Periosteum-Enveloping Hamstring Tendon Graft: Clinical Outcome at 2 to 7 Years Chih-Hwa Chen, M.D., Chih-Hsiang Chang, M.D., Chun-I Su, M.D., Kun-Chung Wang, M.D., Hsien-Tao Liu, M.D., Chung-Ming Yu, M.D., Chak-Bor Wong, M.D., and I-Chun Wang, M.D.
Purpose: In this case-series outcome study, we present our surgical technique for single-bundle anterior cruciate ligament (ACL) reconstruction with periosteum-enveloping hamstring tendon graft at a minimum of 2 years’ follow-up. Methods: From 2000 to 2005, ACL reconstruction with a periosteum-enveloping hamstring tendon graft was performed in 368 patients (372 knees). Of those patients, 312 who completed at least 2 years of follow-up were included for analysis. Four-strand periosteum-enveloping hamstring tendon grafts were used for single-bundle reconstruction. Clinical assessments included the Lysholm knee score, International Knee Documentation Committee score, KT-1000 instrumented testing (MEDmetric, San Diego, CA), thigh muscle assessment, and radiographic evaluation. Radiographs were used to assess femoral and tibial tunnel widening. Results: The 312 study patients were followed up for a mean of 4.6 years (range, 2 to 7 years). The median Lysholm knee scores were 56 points (range, 40 to 70 points) and 95 points (range, 60 to 100 points) before and after surgery, respectively. After reconstruction, 85% of patients could return to moderate or strenuous activity, 5.1% exhibited grade 2 or higher ligament laxity with the anterior drawer test, and 6.1% had a positive pivot shift. Complete range of motion was achieved in 88% of patients. On the basis of International Knee Documentation Committee assessment, 93% of patients had a normal or nearly normal rating. Conclusions: Satisfactory results can be achieved with the periosteumenveloping hamstring tendon graft in single-bundle ACL reconstruction with minimal tunnel widening. Bone tunnel enlargement of more than 1 mm was identified in 5.4% of femoral tunnels and 6.1% of tibial tunnels, which was less than in other studies using comparable fixation. Level of Evidence: Level IV, therapeutic case series.
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nterior cruciate ligament (ACL) reconstruction with semitendinosus and gracilis tendon grafts has become popular in recent years. Successful ACL
From the Department of Orthopaedic Surgery, Chang Gung Memorial Hospital at Keelung, Chang Gung University, College of Medicine, Taoyuan, Taiwan. The authors report no conflict of interest. Received April 7, 2009; accepted November 12, 2009. Address correspondence and reprint requests to Chih-Hwa Chen, M.D., Department of Orthopaedic Surgery, Chang Gung Memorial Hospital at Keelung, 222 Maijin Road, Anle District, Keelung City 204, Taiwan. E-mail: [email protected] © 2010 by the Arthroscopy Association of North America 0749-8063/9196/$36.00 doi:10.1016/j.arthro.2009.11.011
reconstruction necessitates effective osteointegration of these tendon grafts.1,2 In ACL reconstruction surgery, whether single or double bundle, the overall results are satisfactory, with International Knee Documentation Committee (IKDC) and Lysholm scores greater than 88 points.3-6 However, tunnel expansion was noted in up to 30% of patients at final follow-up compared with second postoperative day,7 which may lead to ligament laxity in the future. Tunnel expansion in double-bundle ACL reconstruction may cause tunnel communication over the tibial tunnel in up to 41% of patients, which may impair the advantage of double-bundle reconstruction in the future.8 In the early period after ACL reconstruction, the tendon-bone interface is a weak point
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 26, No 7 (July), 2010: pp 907-917
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comprising a woven bone formation.9 Increased tunnel expansion was noted in studies using an accelerated, brace-free rehabilitation protocol,10,11 and it may be caused by micromotion of the tendon graft in the bone tunnel and mediated by osteoclasts.12 Many studies have focused on tunnel expansion and its possible leading cause.7,10,11,13-15 The periosteum is a bilayered tissue positioned between the outer soft tissue and the inner cortical bone. It comprises an outer fibrous layer and an inner cambium layer. The cambium layer consists of chondroprogenitor and osteoprogenitor cells that, under appropriate induction, have the ability to differentiate into cartilage and bone.16-18 Previous studies have shown that periosteal tissue may enhance healing of the interface between the tendon and bone by forming fibrocartilage and calcified fibrocartilage, and stronger healing strength could be achieved.19,20 Our previous clinical study showed that incorporation of periosteal tissue contributed to normal or nearly normal IKDC ratings in 92% of patients.21 In our early study of ACL reconstruction using hamstring tendon autograft without periosteum, significant tunnel enlargement was noted and abnormal grading of laxity assessment accompanied this in our patients.22 The purpose of this study is to present an ideal surgical technique and prospectively report the clinical outcomes of ACL reconstruction with periosteum-enveloping hamstring tendon graft with evaluation at a minimum of 2 years’ follow-up. We hypothesize that periosteum can accelerate tendon-bone tunnel healing and decrease tunnel expansion in ACL reconstruction. The patients in our previous study21 were enrolled in this series. METHODS Patients From 2000 to 2005, ACL reconstructions with periosteum-enveloping hamstring tendon grafts were performed in 368 patients. Of those patients, 312 with at least 2 years of complete follow-up data were included for analysis. Patient data are presented in Table 1. The indication for surgery was diagnosis of ACL rupture based on clinical evaluation and magnetic resonance imaging (MRI) in a patient with marked instability who wished to maintain his or her preinjury level of activity. The exclusion criteria included grade III medial collateral ligament injury, grade II or III posterior cruciate ligament injury, and grade III lateral collateral or popliteal ligament complex injury. All patients had grade 3 or higher scores on the Lachman and
TABLE 1.
Clinical Data Data
No. of patients Male/female Age at operation (range) (yr) Injury mechanism Sports injury Traffic accident Fall Surgery timing ⬍3 wk 3 wk to 3 mo ⬎3 mo Follow-up (range) (mo)
312 209/103 25 (18-57) 222 (71%) 59 (19%) 31 (10%) 103 (33%) 90 (29%) 119 (38%) 55 (48-84)
NOTE. Data are presented as No. of patients (%), unless otherwise indicated.
anterior drawer tests with a positive pivot-shift test. All arthroscopic surgical procedures were performed by 1 surgeon (C-H.C.). Of the 368 patients who had undergone surgery, 10 had other types of knee injury and could not undergo adequate postoperative assessment, 30 had follow-up of less than 2 years, and 16 had incomplete assessment data. Thus 312 patients were enrolled in this series. Of the patients, 90 (29%) underwent reconstruction 3 weeks to 3 months after injury and 119 (38%) were operated on more than 3 months after injury (Table 1). Surgical Technique The autologous tendon graft was composed of double loops of semitendinosus and gracilis tendon, measuring 10 cm in length. Each tendon graft is fashioned to measure 20 cm in length. Each free tendon end is sutured with a running baseball whipstitch with No. 2 Ethibond suture (Ethicon, Somerville, NJ) (Fig 1). A 3 ⫻ 3– cm periosteum flap was harvested from the anterior tibial cortex through a tibial incision (Fig 2). The periosteum flap was then divided to create two 3 ⫻ 1.5– cm flaps (Fig 3). A 5-mm Mersilene tape (Ethicon) was passed around the looped portion of the graft. The 4-stranded tendon was then sutured together with No. 3-0 Vicryl suture (Ethicon) at a distance of 2 cm from each end. Meanwhile, circumferential reference marks were made 35 mm from the loop end, and the distal reference mark was made according to the measured intra-articular distance between the femoral and tibial openings. The periosteum was wrapped with the cambium layer facing the tunnel wall; it was then sutured on the tendon at both sides with a No. 3-0 Vicryl suture where the tendon graft approached the
PERIOSTEUM-ENVELOPING HAMSTRING TENDON GRAFT
FIGURE 1. Each tendon graft was fashioned to measure 20 cm in length. Each free tendon end was sutured with a running baseball whipstitch with No. 2 Ethibond suture.
tunnel opening (Fig 4). The tibial tunnel was created through the anteromedial portal at a 50° angle, and a guide pin was placed, pointing at the posterior onehalf and medial-lateral center of the native ACL tibial insertion. The tibial tunnel was created with a cannulated reamer of appropriate diameter. Under the direction of the femoral guide instrument with a 7-mm offset, a guide pin was placed retrograde through the tibial tunnel. Then a reamer was used to produce a closed-end femoral tunnel measuring 35 mm in length. The graft was passed into the knee in a retrograde manner through the anterior tibial tunnel opening by use of a Beath pin with the Mersilene tape looped through the end hole. Then the Mersilene tape was passed through the tibial and femoral tunnels and proximally out onto the anterolateral femoral cortex. Another skin incision
FIGURE 2. A 3 ⫻ 3– cm periosteum flap was harvested from the anterior tibial cortex through the tibial incision.
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FIGURE 3. The periosteum flap was divided to create two 3 ⫻ 1.5– cm flaps.
was made over the lateral aspect of the distal thigh, and the Mersilene tape was taken out from the Beath pin and tied rigidly to the surface of the femoral cortex with a washer. Tibial-side fixation was achieved by tying the No. 2 Ethibond suture exiting the tibial tunnel around a bicortical screw and washer at 1 cm distal to the tibial tunnel. The graft was tensioned and secured with full knee extension. The knee was taken through a full range of motion (ROM), and the graft was checked by arthroscopy to ensure appropriate graft placement and the absence of impingement. A cold compression device was applied immediately af-
FIGURE 4. The autologous tendon graft was composed of double loops of semitendinosus and gracilis tendon, measuring 10 cm in length. The periosteum was wrapped with the cambium layer facing the tunnel wall; it was then sutured on the tendon at both sides with a No. 3-0 Vicryl suture where the tendon graft approached the tunnel opening.
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ter the operation, and the knee was placed in a knee brace locked in full extension.21-23 Postoperative Rehabilitation The operated leg was immobilized in the knee brace in full extension for the first week, and full weight bearing was allowed as tolerated starting on the first day after surgery. A rehabilitation program that included quadriceps-strengthening exercises and ROM activities emphasizing full extension was prescribed. Quadriceps isometric exercises and straight leg–raising exercises were started as early as possible. After 4 weeks, movement was permitted within a protected ROM from 0° to 90°. Closed kinetic chain exercises were suggested. At 6 weeks, the brace was unlocked and the establishment of normal gait was anticipated. At 8 weeks, the ROM was expected to progress to complete flexion and extension. Quadriceps and hamstring muscle strength training was performed with a scheduled rehabilitation program, and patients were allowed to resume normal daily activities as soon as possible. Finally, patients were allowed to return to sports at 6 months, and preinjury sports abilities were limited until 9 months later. Follow-Up Evaluation Clinical evaluation of knee function and stability was performed after reconstruction during regular follow-up at our clinics. All patients were evaluated regarding activity level with the IKDC subjective knee evaluation form (Table 2) and the presence of any symptoms, ROM, degree of laxity, and subjective functional assessment. These factors were all rated according to IKDC guidelines. The Lysholm knee score was used to preoperatively and postoperatively evaluate subjective symptoms. KT-1000 arthrometer (MEDmetric, San Diego, CA) tests were performed at 25° of flexion with a standard force of 30 lb (134 N) to measure total anteroposterior translation according to IKDC guidelines. Anterior knee pain was subjectively assessed by patients to determine periosteum
TABLE 2.
Activity Level by IKDC Guidelines
Activity Level Before Injury Preoperatively Final Follow-Up Strenuous (I) Moderate (II) Light (III) Sedentary (IV)
193 (62%) 66 (21%) 31 (10%) 22 (7%)
24 (8%) 29 (9%) 109 (35%) 150 (48%)
171 (55%) 94 (30%) 25 (18%) 22 (7%)
NOTE. Data are presented as No. of patients (%).
donor-site morbidity. Function was assessed with the 1-leg hop test, in which patients were asked to perform a 1-leg hop for a specified distance on the index and normal sides. Three trials for each leg were recorded and averaged, and a ratio of the index knee to normal knee was calculated. Thigh atrophy was defined as the difference in thigh circumference between the involved and contralateral knees at 10 cm proximal to the superior pole of the patella. The Cybex 340 dynamometer (Cybex, New York, NY) was used to measure the difference in flexor and extensor muscle strength between the reconstructed and contralateral knees. Peak extension and flexion torques were isokinetically measured at 60°/s, 90°/s, and 180°/s. The side-to-side ratio (peak muscle torque of involved side/peak muscle torque of contralateral side ⫻ 100%) was used to measure thigh muscle strength. Anteroposterior and lateral weight-bearing radiographs were obtained preoperatively, annually after surgery, and at the final follow-up visit. The bone tunnels on the anteroposterior and lateral radiographs were measured by calipers at 3 months, at 2 years, and at the final follow-up. To evaluate bone tunnel enlargement, the sclerotic margins of the femoral and tibial tunnels were measured at the widest part of the tunnel. The measurements were corrected for radiographic magnification with a marker included on the films. Maximum tunnel widening during follow-up was compared with the initially drilled tunnel size. Six patients underwent MRI study. All of them had had reinjury of the operated knee during follow-up. The MRI study included transverse views of the femoral and tibial tunnels and a sagittal view of the knee for evaluating graft condition and graft– bone tunnel incorporation. Statistical Analysis The paired Student t test was used to compare preoperative and postoperative ligament laxity, thigh circumference, and extensor and flexor strength ratio. Comparison of the preoperative and postoperative Lysholm scores was made by use of a paired Student t test. The level of statistical significance is assumed at P ⬍ .05. RESULTS Associated Injury Detected During Surgery In this series significant non-ACL injuries were excluded, such as grade III medial collateral ligament injury, grade II or III posterior cruciate ligament in-
PERIOSTEUM-ENVELOPING HAMSTRING TENDON GRAFT TABLE 3.
Lysholm Knee Scores
Rating Excellent (95-100 points) Good (84-94 points) Fair (65-83 points) Poor (⬍65 points) Mean ⫾ SD*
Preoperatively
Final Follow-Up
0 0 68 (22%) 144 (78%) 56.4 ⫾ 10.2
193 (62%) 93 (30%) 18 (6%) 8 (2%) 94.5 ⫾ 8.4
NOTE. Data are presented as No. of patients (%), unless otherwise indicated. *P ⬍ .01, paired Student t test.
jury, and grade III lateral collateral or popliteal ligament complex injury. The most common injury associated with ACL tear was meniscus tear, which affected 197 patients (63%). Chondral injury was the second most commonly associated injury, affecting 60 patients (19%). Grade I or II medial collateral ligament tear, posteromedial/posterolateral injury, and grade I posterior cruciate ligament injury were also observed. These injuries affected 38 patients (12%), 21 patients (7%), and 18 patients (6%), respectively. Lysholm Knee Scores The median preoperative Lysholm knee score was 56 points (95% confidence interval, 45.2 to 76.6 points). At final follow-up, the median score was 95 points (95% confidence interval, 86.1 to 100 points) (P ⬍ .01) (Table 3). In total, 286 patients (92%) had good to excellent results, 18 (6%) had fair results, and 8 (2%) had poor results. IKDC Scores Activity: With regard to preinjury activity level, 259 patients participated in strenuous and moderate activities. After injury and before surgery, 259 (83%) were only able to participate in light or sedentary levels of activity. At the final postoperative follow-up, 257 patients (83%) were participating in moderate to strenuous activities (Table 2). Knee Function by Patient Subjective Assessment: Preoperative self-assessment, according to the IKDC subjective knee evaluation form, showed that the patients’ status was abnormal in 212 patients (68%) and severely abnormal in 100 (32%). At final follow-up assessment after reconstruction, 289 patients (93%) subjectively rated their knee function as normal or nearly normal. Symptoms: The symptom sections of the IKDC form assessed pain, swelling, and partial or complete giving way. Of the patients, 20 (6.4%) reported pain
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during moderate or strenuous activities and 18 (5.7%) reported swelling during moderate or strenuous activities. Moreover, 17 patients (5.4%) displayed symptoms of partial giving way during moderate or strenuous activities, and 3 (0.96%) reported occasions of full giving way during moderate or strenuous activities. Range of Motion: At the last follow-up, all patients could perform full knee extension, and 273 patients (87.5%) with differences in full flexion of 5° or less between the normal and reconstructed limbs were given a normal rating. The rating was nearly normal in 20 patients (6.4%) with 6° to 15° deficits in flexion, abnormal in 14 patients (4.5%) with 16° to 25° deficits in flexion, and severely abnormal in 5 patients (1.6%) with greater than 25° deficits in flexion (Table 4). Ligament Laxity: All patients received a KT-1000 arthrometer evaluation with 25° of flexion to preoperatively and postoperatively evaluate anterior displacement. Preoperatively, the mean anterior displacement was 11.70 ⫾ 1.86 mm. At final follow-up, KT-1000 examination showed 0 to 2 mm of anterior translation in 271 patients (86.9%), 3 to 5 mm of anterior laxity in 25 (8%), and more than 5 mm of translation in 16 (5.1%). The differences are measured as side-to-side differences. The mean anterior displacement at final follow-up was 1.62 ⫾ 1.58 mm. There was a significant difference between preoperative and postoperative evaluation (P ⬍ .01) (Table 5). Patellofemoral Crepitus: Patellofemoral crepitus with mild discomfort was noted in 16 patients, and
TABLE 4. Normal
IKDC Scores Nearly Severely Normal Abnormal Abnormal
Category Knee function 255 Symptoms 252 Pain 255 Swelling 259 Partial giving way 260 Full giving way 296 ROM 273 Ligament laxity 256 Patellofemoral crepitus 268 Donor site 295 Radiograph 282 Functional test 263 Final rating 249 (80%) 40
40 40 37 35 35 13 20 40
16 16 16 15 13 2 14 10
21 16 13 3 18 11 30 15 (13%) 16 (5%)
NOTE. Data are presented as No. of patients.
1 4 4 3 4 1 5 6 7 1 1 4 7 (2%)
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TABLE 5.
KT-1000 Evaluation of Anterior Knee Laxity Preoperatively Postoperatively
Anterior drawer test Grade I (0-5 mm) 0 Grade II (6-10 mm) 0 Grade III (11-15 mm) 274 (88%) Grade IV (⬎15 mm) 38 (12%) KT-1000 test for IKDC rating Normal (0-2 mm) 0 Nearly normal (3-5 mm) 0 Abnormal (6-10 mm) 0 Severely abnormal (⬎10 mm) 312 Mean ⫾ SD* 11.70 ⫾ 1.86
296 (94.9%) 10 (3.2%) 6 (1.9%) 0 271 (86.9%) 25 (8%) 10 (3.2%) 6 (1.9%) 1.62 ⫾ 1.58
NOTE. Data are presented as No. of patients (%), unless otherwise indicated. *P ⬍ .01 (paired Student t test) for comparison between preoperative and postoperative examination.
patellofemoral crepitus with moderate or severe pain on squatting occurred in 7 patients. Donor-site morbidity: There were 42 patients who had a minor hematoma over the periosteum harvest site for about 2 to 3 weeks, and the hematoma had resolved gradually without any subsequent procedure. No residual discomfort at the donor site was reported in 304 patients (97.5%). However, 8 patients (2.5%) had some tenderness, numbness, or irritation over the incision area. Radiographic Findings: Normal radiography in the joint space was noted in 263 patients (84.29%). Minimal radiologic deterioration on radiography at the final examination was found in 18 patients (5.7%), and joint space narrowing (2 to 4 mm wide) was observed in 11 patients (3.5%). One patient had significant medial joint space narrowing measuring greater than 4 mm. Functional Test: On functional testing with a 1-leg hop of the injured leg, 255 patients (81.7%) achieved a distance of 90% or more of that achieved with the normal leg, 40 patients (12.8%) achieved a distance of 76% to 89% of the normal leg, and 17 patients (5.5%) achieved hops of less than 70% of the distance. TABLE 6.
Overall Rating: The overall rating according to IKDC criteria was normal in 249 patients (80%), nearly normal in 40 (12.8%), abnormal in 16 (5%), and severely abnormal in 7 (2%) (Table 4). Thigh Muscle Atrophy and Muscle Strength Measurement of thigh circumference showed that 253 patients (81%) had a difference of less than 10 mm between their reconstructed and normal limbs whereas 44 patients had a difference of more than 10 mm. The Cybex study showed that 249 patients (80%) achieved extensor muscle strength in the reconstructed knee at 90% or more of normal knee strength and 47 patients (15%) recovered 80% to 90% of normal knee strength. Moreover, 234 patients (75%) achieved 90% or more of flexor muscle strength in the reconstructed knee, and 53 patients (17%) recovered 80% to 90% of normal knee strength. A statistically significant difference existed in thigh girth difference, extensor strength ratio, and flexor strength ratio before and after reconstruction after a minimum 2 years of follow-up (Table 6). Tunnel Enlargement At final follow-up, radiographs showed minimal bone tunnel widening. Assessment of overall tunnel enlargement showed bone tunnel enlargement of more than 1 mm in 5.4% of femoral tunnels and 6.1% of tibial tunnels (Fig 5). On MRI study in the 6 patients who had had reinjury of the operated knee, the tendon graft condition was tight and the incorporation between tendon graft and bone tunnel was good. Minimal tunnel widening was noted, and there was no fluid in the tunnel based on T2-weighted magnetic resonance images (Fig 6). Complications Eight patients had mild abscess at the suture sight; all recovered after suture removal. Ten patients complained about numbness over the tibial skin incision. Of these, 6 had nearly recovered after 6 months and 4
Difference in Thigh Muscle Atrophy, Flexor Muscle Strength, and Extensor Muscle Strength
Thigh Muscle Parameters Thigh girth difference Extensor strength ratio Flexor strength ratio
Preoperatively/Final Follow-Up (Mean ⫾ SD) (mm)
P Value*
17.07 ⫾ 6.58/8.81 ⫾ 6.42 77.92 ⫾ 9.12/90.07 ⫾ 9.81 80.18 ⫾ 11.72/90.21 ⫾ 11.22
⬍.01 ⬍.01 ⬍.01
*Comparison between preoperative and final follow-up examination by paired Student t test.
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FIGURE 5. Anteroposterior and lateral weight-bearing radiographs showed no tunnel expansion at final follow-up.
have residual numbness. Complete ACL rerupture was noted in 3 patients, and partial tear was noted in 4 patients. All of them had had reinjury of the knee. DISCUSSION ACL reconstruction surgery is a well-established technique, and the overall results are satisfactory, with IKDC and Lysholm scores greater than 88 points.3-6 Recently, many studies have focused on tunnel expansion after ACL reconstruction with hamstring autografts. Tunnel expansion has been a major concern after ACL reconstruction with hamstring tendon autografts. The possible causes of tunnel widening have been discussed, such as tunnel position,13 position of the fixation sites and type of fixation device,14,15 and timing of rehabilitation.10,11 Tunnel expansion is significant because of the greater distance from the normal insertion site and the biomechanical point of action of the ACL. Iorio et al.13 found that an anatomic surgical technique and a less aggressive rehabilitation process influenced the amount of tunnel enlargement after ACL reconstruction. The increased distance creates a potentially larger force moment during graft cycling, which may lead to greater bone tunnel expansion.13 The fixation methods also influence the rate of tunnel expansion. Fauno and Kaalund14 found that there was a significant reduction in tunnel widening in both the femur and the tibia when fixation points were close to the joint compared with systems where the fixation points were further apart.
Baumfeld et al.15 found that the EndoButton suspensory fixation system (Ethicon) had significantly more tunnel expansion compared with double– cross pin fixation within the tunnel. Early and aggressive rehabilitation also leads to tunnel expansion. Hantes et al.11 studied about brace-free, unrestricted ROM and full weight bearing in one group and restricted ROM and partial weight bearing in another group. They found that early motion increased the bone tunnel enlargement. Vadala et al.10 agreed with the conclusion that an accelerated, brace-free rehabilitation protocol can increase the bone tunnel enlargement. Micromotion of tendon graft in bone tunnel may be the leading cause contributing to tunnel widening. In a study by Rodeo et al.,12 osteoclasts were found at the tunnel aperture, and they noted that the graft tunnel may impair early graft incorporation and may lead to osteoclast-mediated bone resorption. Incorporation of tendon and bone is a major concern when performing ACL reconstruction, which may be compromised by tunnel expansion. However, the clinical results are not influenced by tunnel expansion based on current evidence,14,15,24 whereas laxity of the tendon graft and difficulties with revision are of concern. The periosteum consists of multipotent mesodermal cells that are capable of differentiating into various types of connective tissue and bone.16,25 Histologic examination of the periosteum showed the presence of an outer “fibrous layer” and an inner “cambium layer.” The fibrous layer contains fibroblasts, and the cambium layer contains progenitor cells.16 By attach-
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FIGURE 6. On MRI, the tendon graft condition was tight and the incorporation between tendon graft and 1 tunnel was good. Minimal tunnel widening was noted, and there was no fluid in the tunnel based on T2weighted magnetic resonance images.
ing the periosteum onto the tendon-bone interface, the fibroblasts in the fibrous layer could develop into scar tissue that contains collagen fibers that hold the tendon part, and the progenitor cells in the cambium layer can differentiate into osteoblasts and chondroblasts and subsequently into fibrocartilage and calcified fibrocartilage. The progenitor cells in the cambium layer of the periosteum can facilitate bony ingrowth into the collagenous tissue formed by the fibroblasts in the fibrous layer of the periosteum and can induce ossification and bone formation.25 In 1930 Burman and Umansky26 found that a free periosteal transplant wrapped around a tendon could generate bony ingrowth in the tendon as early as 2 weeks after surgery. In a rabbit model the periosteum was applied to tendon grafts by enveloping the tendon in a bone tunnel.19,20 Histologic examination showed that bony ingrowth into the cambium layer appeared at 4 weeks and that interdigitation occurred between the perios-
teum tissue and the tendon. The fibrous layer from the wrapped periosteum progressively became a collagen fiber– bone intermixture with anchorage, and incorporation and organization on the interface developed with time. Biomechanical testing showed a progressive increase in tendon pullout strength followed by bony ingrowth, mineralization, and incorporation of the healing tissue in the periosteum group. It also showed that there was a significant increase in the interface strength between the periosteum and control groups at 8 and 12 weeks. It appears that periosteum offers a powerful inductive ability between the tendon and the bone tunnel to incorporate healing. Our previous clinical study in 1998 showed that the use of hamstring tendon grafts without periosteum in ACL reconstruction resulted in enlargement of more than 1 mm in 19% of femoral tunnels and 12% of tibial tunnels.22 The overall IKDC rating was normal or nearly normal in 88% of patients.22 For better
PERIOSTEUM-ENVELOPING HAMSTRING TENDON GRAFT clinical results, with less tunnel expansion, and on the basis of these studies, we considered the periosteum potentially useful for stimulating and enhancing healing at the tendon-bone interface so that a satisfactory clinical result could be expected. We applied this concept to ACL reconstruction to enhance tendonbone healing by using autologous periosteum with the cambium layer facing toward the tunnel wall. Our previous study on the clinical outcome of using a hamstring tendon graft for ACL reconstruction showed that the overall IKDC rating was normal or nearly normal in 92% of patients. Furthermore, the overall 100-point subjective knee score was 94, and 7% of patients had grade 2 or greater ligament laxity.21 Better clinical results and less tunnel expansion could be achieved with this technique. Siebold et al.7 tried to determine whether a stepped router could reduce the postoperative tunnel expansion, and they found that there was no difference in tunnel expansion between extraction versus compaction drilling. On the basis of their study, the possible reason that our series had less tunnel expansion is not the compaction drilling. Fauno and Kaalund14 and Baumfeld et al.15 compared transfemoral fixation (TransFix; Arthrex Inc., Naples, FL) and interference screws (Arthrex) with extracortical fixation (EndoButton, Smith & Nephew, Memphis, TN) regarding tunnel expansion. They found that the suspensory fixation (EndoButton) had greater tunnel expansion, although the clinical results were similar within 2 years of follow-up. Our femoral fixation type in this series was Mersilene tape tied rigidly to the surface of the femoral cortex with a washer, and it is similar to EndoButton fixation, a suspensory fixation. Tunnel expansion was much less in our series; even we use the suspensory fixation type, which was proved having greater tunnel expansion by Fauno and Kaalund and Baumfeld et al. The difference between our series and those of Fauno and Kaalund and Baumfeld et al. is that we added periosteum where the graft approached the tunnel opening. The periosteum inside the femoral and tibial tunnel approaching the tunnel opening could accelerate the tendon-bone incorporation, decrease the micromotion of tendon graft due to plugging effect, and prevent synovial fluid influx. In their study Clatworthy et al.27 indicated that synovial fluid may influx between the tendon and bone tunnel and may impair tendon-bone healing and cause micromotion of the tendon-bone interface, possibly inducing osteolysis and eventual radiographic evidence of tunnel enlargement. In our series periosteum may have acted to seal the intraarticular tunnel opening in the early period to avoid
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synovial fluid influx between the tendon and the bone. Undesirable tendon motion in the tunnel and synovial fluid influx that may result in tunnel expansion can be avoided. Robert and Es-Sayeh28 studied 2 groups with and without a periosteal flap over the femoral tunnel, and they found that there was a significant reduction in tunnel enlargement with the periosteal flap, which is compatible with our results. Vadala et al.10 and Hantes et al.11 found less tunnel expansion in the conservatively treated group with partial weight bearing and restricted ROM. In contrast, in our series, we allowed full weight bearing on the second postoperative day and gradually increased ROM until full ROM was allowed at 8 weeks. Our result regarding tunnel expansion was much lesser, and it may have been caused by the effect of periosteum. Simonian et al.29 found that tunnel enlargement usually could be measured during the initial 3 months of followup, which should remind us that early protection of the operated knee is needed. In total 6 patients in our study had had reinjury of the operated knee during follow-up and underwent MRI study. On the MRI study, we could evaluate the tightness of the tendon graft and observe the incorporation of tendon and bone by examining the bone tunnel, to determine whether there was fluid with soft tissue content in the bone tunnel. In our patients the tendon graft condition was tight and the incorporation between tendon graft and bone tunnel was good without fluid in the tunnels based on T2-weighted magnetic resonance images. There was no soft tissue noted in the bone tunnel at the tendon-bone junction, which means that there was no fibrous tendon insertion and the tendon-bone healing was good. If we consider the tunnel expansion to be related to tendon graft loosening or reinjury to be related to tendon graft tear or laxity, MRI is a good tool to evaluate the tendon condition and tendon-bone incorporation. On the basis of animal studies, previous clinical studies of other authors, and our present clinical follow-up, we suggest that the addition of periosteum may decrease tunnel widening when used in hamstring ACL reconstruction with suspensory fixation. In this series tunnel enlargement of more than 1 mm was identified in only 5.4% of femoral tunnels and 6.1% of tibial tunnels. A previous clinical study in 2004 showed that bone tunnel enlargement of more than 1 mm was identified in 5% of femoral tunnels and 6% of tibial tunnels.21 In clinical practice the periosteum-enveloping technique was applied to ACL reconstruction with hamstring tendon grafts, and a satisfactory clinical result was achieved. Periosteum is easy to harvest from the proximal tibia through a routine incision for hamstring tendon har-
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vesting, and it takes approximately 3 more minutes to harvest. After tendon graft was well prepared, it took about 5 more minutes to suture the periosteum onto the tendon graft. The limitations of this study include that this is a case-series study, so there is no comparison group treated without periosteum. We could not compare the clinical difference in ACL reconstruction with and without periosteum. There was also a lack of comparison between “aggressive” and “nonaggressive” rehabilitation protocols for evaluation of the effect of periosteal flap. Biomechanical studies are also needed to evaluate whether the periosteum can make the tendon-bone incorporation stronger. Regarding tunnel expansion, there is no evidence that tunnel widening could impair the clinical result of ACL reconstruction. The maximum follow-up time is 7 years, and a longterm follow-up study may be needed in the future to evaluate the correlation between clinical outcome and imaging studies.
8. 9.
10.
11.
12.
13. 14.
CONCLUSIONS The study shows that satisfactory results can be achieved with the periosteum-enveloping hamstring tendon graft in single-bundle ACL reconstruction with minimal tunnel widening. Bone tunnel enlargement of more than 1 mm was identified in 5.4% of femoral tunnels and 6.1% of tibial tunnels, which was less than in other studies using comparable fixation. REFERENCES
15.
16. 17. 18. 19.
1. Goradia VK, Rochat MC, Grana WA, Rohrer MD, Prasad HS. Tendon-to-bone healing of a semitendinosus tendon autograft used for ACL reconstruction in a sheep model. Am J Knee Surg 2000;13:143-151. 2. Rodeo SA, Arnoczky SP, Torzilli PA, Hidaka C, Warren RF. Tendon-healing in a bone tunnel. A biomechanical and histological study in the dog. J Bone Joint Surg Am 1993;75:1795-1803. 3. Toritsuka Y, Amano H, Kuwano M, et al. Outcome of doublebundle ACL reconstruction using hamstring tendons. Knee Surg Sports Traumatol Arthrosc 2009;17:456-463. 4. Shelbourne KD, Gray T. Minimum 10-year results after anterior cruciate ligament reconstruction: How the loss of normal knee motion compounds other factors related to the development of osteoarthritis after surgery. Am J Sports Med 2009; 37:471-480. 5. Streich NA, Friedrich K, Gotterbarm T, Schmitt H. Reconstruction of the ACL with a semitendinosus tendon graft: A prospective randomized single blinded comparison of doublebundle versus single-bundle technique in male athletes. Knee Surg Sports Traumatol Arthrosc 2008;16:232-238. 6. Kim SJ, Jo SB, Kumar P, Oh KS. Comparison of single- and double-bundle anterior cruciate ligament reconstruction using quadriceps tendon-bone autografts. Arthroscopy 2009;25:70-77. 7. Siebold R, Kiss ZS, Morris HG. Effect of compaction drilling
20. 21.
22.
23. 24.
25.
during ACL reconstruction with hamstrings on postoperative tunnel widening. Arch Orthop Trauma Surg 2008;128:461468. Siebold R. Observations on bone tunnel enlargement after double-bundle anterior cruciate ligament reconstruction. Arthroscopy 2007;23:291-298. Oguma H, Murakami G, Takahashi-Iwanaga H, Aoki M, Ishii S. Early anchoring collagen fibers at the bone-tendon interface are conducted by woven bone formation: Light microscope and scanning electron microscope observation using a canine model. J Orthop Res 2001;19:873-880. Vadala A, Iorio R, De Carli A, et al. The effect of accelerated, brace free, rehabilitation on bone tunnel enlargement after ACL reconstruction using hamstring tendons: A CT study. Knee Surg Sports Traumatol Arthrosc 2007;15:365-371. Hantes ME, Mastrokalos DS, Yu J, Paessler HH. The effect of early motion on tibial tunnel widening after anterior cruciate ligament replacement using hamstring tendon grafts. Arthroscopy 2004;20:572-580. Rodeo SA, Kawamura S, Kim HJ, Dynybil C, Ying L. Tendon healing in a bone tunnel differs at the tunnel entrance versus the tunnel exit: An effect of graft-tunnel motion? Am J Sports Med 2006;34:1790-1800. Iorio R, Vadala A, Argento G, Di Sanzo V, Ferretti A. Bone tunnel enlargement after ACL reconstruction using autologous hamstring tendons: A CT study. Int Orthop 2007;31:49-55. Fauno P, Kaalund S. Tunnel widening after hamstring anterior cruciate ligament reconstruction is influenced by the type of graft fixation used: A prospective randomized study. Arthroscopy 2005;21:1337-1341. Baumfeld JA, Diduch DR, Rubino LJ, et al. Tunnel widening following anterior cruciate ligament reconstruction using hamstring autograft: A comparison between double cross-pin and suspensory graft fixation. Knee Surg Sports Traumatol Arthrosc 2008;16:1108-1113. Augustin G, Antabak A, Davila S. The periosteum. Part 1: Anatomy, histology and molecular biology. Injury 2007;38: 1115-1130. Ritsila V, Alhopuro S, Rintala A. Bone formation with free periosteum. An experimental study. Scand J Plast Reconstr Surg 1972;6:51-56. Rubak JM. Osteochondrogenesis of free periosteal grafts in the rabbit iliac crest. Acta Orthop Scand 1983;54:826-831. Chen CH, Chen WJ, Shih CH, Yang CY, Liu SJ, Lin PY. Enveloping the tendon graft with periosteum to enhance tendon-bone healing in a bone tunnel: A biomechanical and histologic study in rabbits. Arthroscopy 2003;19:290-296. Youn I, Jones DG, Andrews PJ, Cook MP, Suh JK. Periosteal augmentation of a tendon graft improves tendon healing in the bone tunnel. Clin Orthop Relat Res 2004:223-231. Chen CH, Chen WJ, Shih CH, Chou SW. Arthroscopic anterior cruciate ligament reconstruction with periosteum-enveloping hamstring tendon graft. Knee Surg Sports Traumatol Arthrosc 2004;12:398-405. Chen CH, Chen WJ, Wu CC, Shih CH. Arthroscopic anterior cruciate ligament reconstruction with quadruple semitendinosus and gracilis tendon autograft; surgical technique and clinical results. J Orthop Surg 1998; 6:61-70. Chen CH, Chen WJ, Shih CH. Enveloping of periosteum on the hamstring tendon graft in anterior cruciate ligament reconstruction. Arthroscopy 2002;18:27e. Fules PJ, Madhav RT, Goddard RK, Newman-Sanders A, Mowbray MA. Evaluation of tibial bone tunnel enlargement using MRI scan cross-sectional area measurement after autologous hamstring tendon ACL replacement. Knee 2003;10:87-91. Ritsila VA, Santavirta S, Alhopuro S, et al. Periosteal and perichondral grafting in reconstructive surgery. Clin Orthop Relat Res 1994:259-265.
PERIOSTEUM-ENVELOPING HAMSTRING TENDON GRAFT 26. Burman MS, Umansky M. An experimental study of free periosteal transplants, wrapped around tendon. With a review of the literature. J Bone Joint Surg 1930;12:579-594. 27. Clatworthy MG, Annear P, Bulow JU, Bartlett RJ. Tunnel widening in anterior cruciate ligament reconstruction: A prospective evaluation of hamstring and patella tendon grafts. Knee Surg Sports Traumatol Arthrosc 1999;7:138145.
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28. Robert H, Es-Sayeh J. The role of periosteal flap in the prevention of femoral widening in anterior cruciate ligament reconstruction using hamstring tendons. Knee Surg Sports Traumatol Arthrosc 2004;12:30-35. 29. Simonian PT, Erickson MS, Larson RV, O’Kane JW. Tunnel expansion after hamstring anterior cruciate ligament reconstruction with 1-incision EndoButton femoral fixation. Arthroscopy 2000;16:707-714.
Purpose: In this case-series outcome study, we present our surgical technique for single-bundle anterior cruciate ligament (ACL) reconstruction with periosteum-enveloping hamstring tendon graft at a minimum of 2 years’ follow-up. Methods: From 2000 to 2005, ACL reconstruction with a periosteum-enveloping hamstring tendon graft was performed in 368 patients (372 knees). Of those patients, 312 who completed at least 2 years of follow-up were included for analysis. Four-strand periosteum-enveloping hamstring tendon grafts were used for single-bundle reconstruction. Clinical assessments included the Lysholm knee score, International Knee Documentation Committee score, KT-1000 instrumented testing (MEDmetric, San Diego, CA), thigh muscle assessment, and radiographic evaluation. Radiographs were used to assess femoral and tibial tunnel widening. Results: The 312 study patients were followed up for a mean of 4.6 years (range, 2 to 7 years). The median Lysholm knee scores were 56 points (range, 40 to 70 points) and 95 points (range, 60 to 100 points) before and after surgery, respectively. After reconstruction, 85% of patients could return to moderate or strenuous activity, 5.1% exhibited grade 2 or higher ligament laxity with the anterior drawer test, and 6.1% had a positive pivot shift. Complete range of motion was achieved in 88% of patients. On the basis of International Knee Documentation Committee assessment, 93% of patients had a normal or nearly normal rating. Conclusions: Satisfactory results can be achieved with the periosteumenveloping hamstring tendon graft in single-bundle ACL reconstruction with minimal tunnel widening. Bone tunnel enlargement of more than 1 mm was identified in 5.4% of femoral tunnels and 6.1% of tibial tunnels, which was less than in other studies using comparable fixation. Level of Evidence: Level IV, therapeutic case series.
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nterior cruciate ligament (ACL) reconstruction with semitendinosus and gracilis tendon grafts has become popular in recent years. Successful ACL
From the Department of Orthopaedic Surgery, Chang Gung Memorial Hospital at Keelung, Chang Gung University, College of Medicine, Taoyuan, Taiwan. The authors report no conflict of interest. Received April 7, 2009; accepted November 12, 2009. Address correspondence and reprint requests to Chih-Hwa Chen, M.D., Department of Orthopaedic Surgery, Chang Gung Memorial Hospital at Keelung, 222 Maijin Road, Anle District, Keelung City 204, Taiwan. E-mail: [email protected] © 2010 by the Arthroscopy Association of North America 0749-8063/9196/$36.00 doi:10.1016/j.arthro.2009.11.011
reconstruction necessitates effective osteointegration of these tendon grafts.1,2 In ACL reconstruction surgery, whether single or double bundle, the overall results are satisfactory, with International Knee Documentation Committee (IKDC) and Lysholm scores greater than 88 points.3-6 However, tunnel expansion was noted in up to 30% of patients at final follow-up compared with second postoperative day,7 which may lead to ligament laxity in the future. Tunnel expansion in double-bundle ACL reconstruction may cause tunnel communication over the tibial tunnel in up to 41% of patients, which may impair the advantage of double-bundle reconstruction in the future.8 In the early period after ACL reconstruction, the tendon-bone interface is a weak point
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comprising a woven bone formation.9 Increased tunnel expansion was noted in studies using an accelerated, brace-free rehabilitation protocol,10,11 and it may be caused by micromotion of the tendon graft in the bone tunnel and mediated by osteoclasts.12 Many studies have focused on tunnel expansion and its possible leading cause.7,10,11,13-15 The periosteum is a bilayered tissue positioned between the outer soft tissue and the inner cortical bone. It comprises an outer fibrous layer and an inner cambium layer. The cambium layer consists of chondroprogenitor and osteoprogenitor cells that, under appropriate induction, have the ability to differentiate into cartilage and bone.16-18 Previous studies have shown that periosteal tissue may enhance healing of the interface between the tendon and bone by forming fibrocartilage and calcified fibrocartilage, and stronger healing strength could be achieved.19,20 Our previous clinical study showed that incorporation of periosteal tissue contributed to normal or nearly normal IKDC ratings in 92% of patients.21 In our early study of ACL reconstruction using hamstring tendon autograft without periosteum, significant tunnel enlargement was noted and abnormal grading of laxity assessment accompanied this in our patients.22 The purpose of this study is to present an ideal surgical technique and prospectively report the clinical outcomes of ACL reconstruction with periosteum-enveloping hamstring tendon graft with evaluation at a minimum of 2 years’ follow-up. We hypothesize that periosteum can accelerate tendon-bone tunnel healing and decrease tunnel expansion in ACL reconstruction. The patients in our previous study21 were enrolled in this series. METHODS Patients From 2000 to 2005, ACL reconstructions with periosteum-enveloping hamstring tendon grafts were performed in 368 patients. Of those patients, 312 with at least 2 years of complete follow-up data were included for analysis. Patient data are presented in Table 1. The indication for surgery was diagnosis of ACL rupture based on clinical evaluation and magnetic resonance imaging (MRI) in a patient with marked instability who wished to maintain his or her preinjury level of activity. The exclusion criteria included grade III medial collateral ligament injury, grade II or III posterior cruciate ligament injury, and grade III lateral collateral or popliteal ligament complex injury. All patients had grade 3 or higher scores on the Lachman and
TABLE 1.
Clinical Data Data
No. of patients Male/female Age at operation (range) (yr) Injury mechanism Sports injury Traffic accident Fall Surgery timing ⬍3 wk 3 wk to 3 mo ⬎3 mo Follow-up (range) (mo)
312 209/103 25 (18-57) 222 (71%) 59 (19%) 31 (10%) 103 (33%) 90 (29%) 119 (38%) 55 (48-84)
NOTE. Data are presented as No. of patients (%), unless otherwise indicated.
anterior drawer tests with a positive pivot-shift test. All arthroscopic surgical procedures were performed by 1 surgeon (C-H.C.). Of the 368 patients who had undergone surgery, 10 had other types of knee injury and could not undergo adequate postoperative assessment, 30 had follow-up of less than 2 years, and 16 had incomplete assessment data. Thus 312 patients were enrolled in this series. Of the patients, 90 (29%) underwent reconstruction 3 weeks to 3 months after injury and 119 (38%) were operated on more than 3 months after injury (Table 1). Surgical Technique The autologous tendon graft was composed of double loops of semitendinosus and gracilis tendon, measuring 10 cm in length. Each tendon graft is fashioned to measure 20 cm in length. Each free tendon end is sutured with a running baseball whipstitch with No. 2 Ethibond suture (Ethicon, Somerville, NJ) (Fig 1). A 3 ⫻ 3– cm periosteum flap was harvested from the anterior tibial cortex through a tibial incision (Fig 2). The periosteum flap was then divided to create two 3 ⫻ 1.5– cm flaps (Fig 3). A 5-mm Mersilene tape (Ethicon) was passed around the looped portion of the graft. The 4-stranded tendon was then sutured together with No. 3-0 Vicryl suture (Ethicon) at a distance of 2 cm from each end. Meanwhile, circumferential reference marks were made 35 mm from the loop end, and the distal reference mark was made according to the measured intra-articular distance between the femoral and tibial openings. The periosteum was wrapped with the cambium layer facing the tunnel wall; it was then sutured on the tendon at both sides with a No. 3-0 Vicryl suture where the tendon graft approached the
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FIGURE 1. Each tendon graft was fashioned to measure 20 cm in length. Each free tendon end was sutured with a running baseball whipstitch with No. 2 Ethibond suture.
tunnel opening (Fig 4). The tibial tunnel was created through the anteromedial portal at a 50° angle, and a guide pin was placed, pointing at the posterior onehalf and medial-lateral center of the native ACL tibial insertion. The tibial tunnel was created with a cannulated reamer of appropriate diameter. Under the direction of the femoral guide instrument with a 7-mm offset, a guide pin was placed retrograde through the tibial tunnel. Then a reamer was used to produce a closed-end femoral tunnel measuring 35 mm in length. The graft was passed into the knee in a retrograde manner through the anterior tibial tunnel opening by use of a Beath pin with the Mersilene tape looped through the end hole. Then the Mersilene tape was passed through the tibial and femoral tunnels and proximally out onto the anterolateral femoral cortex. Another skin incision
FIGURE 2. A 3 ⫻ 3– cm periosteum flap was harvested from the anterior tibial cortex through the tibial incision.
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FIGURE 3. The periosteum flap was divided to create two 3 ⫻ 1.5– cm flaps.
was made over the lateral aspect of the distal thigh, and the Mersilene tape was taken out from the Beath pin and tied rigidly to the surface of the femoral cortex with a washer. Tibial-side fixation was achieved by tying the No. 2 Ethibond suture exiting the tibial tunnel around a bicortical screw and washer at 1 cm distal to the tibial tunnel. The graft was tensioned and secured with full knee extension. The knee was taken through a full range of motion (ROM), and the graft was checked by arthroscopy to ensure appropriate graft placement and the absence of impingement. A cold compression device was applied immediately af-
FIGURE 4. The autologous tendon graft was composed of double loops of semitendinosus and gracilis tendon, measuring 10 cm in length. The periosteum was wrapped with the cambium layer facing the tunnel wall; it was then sutured on the tendon at both sides with a No. 3-0 Vicryl suture where the tendon graft approached the tunnel opening.
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ter the operation, and the knee was placed in a knee brace locked in full extension.21-23 Postoperative Rehabilitation The operated leg was immobilized in the knee brace in full extension for the first week, and full weight bearing was allowed as tolerated starting on the first day after surgery. A rehabilitation program that included quadriceps-strengthening exercises and ROM activities emphasizing full extension was prescribed. Quadriceps isometric exercises and straight leg–raising exercises were started as early as possible. After 4 weeks, movement was permitted within a protected ROM from 0° to 90°. Closed kinetic chain exercises were suggested. At 6 weeks, the brace was unlocked and the establishment of normal gait was anticipated. At 8 weeks, the ROM was expected to progress to complete flexion and extension. Quadriceps and hamstring muscle strength training was performed with a scheduled rehabilitation program, and patients were allowed to resume normal daily activities as soon as possible. Finally, patients were allowed to return to sports at 6 months, and preinjury sports abilities were limited until 9 months later. Follow-Up Evaluation Clinical evaluation of knee function and stability was performed after reconstruction during regular follow-up at our clinics. All patients were evaluated regarding activity level with the IKDC subjective knee evaluation form (Table 2) and the presence of any symptoms, ROM, degree of laxity, and subjective functional assessment. These factors were all rated according to IKDC guidelines. The Lysholm knee score was used to preoperatively and postoperatively evaluate subjective symptoms. KT-1000 arthrometer (MEDmetric, San Diego, CA) tests were performed at 25° of flexion with a standard force of 30 lb (134 N) to measure total anteroposterior translation according to IKDC guidelines. Anterior knee pain was subjectively assessed by patients to determine periosteum
TABLE 2.
Activity Level by IKDC Guidelines
Activity Level Before Injury Preoperatively Final Follow-Up Strenuous (I) Moderate (II) Light (III) Sedentary (IV)
193 (62%) 66 (21%) 31 (10%) 22 (7%)
24 (8%) 29 (9%) 109 (35%) 150 (48%)
171 (55%) 94 (30%) 25 (18%) 22 (7%)
NOTE. Data are presented as No. of patients (%).
donor-site morbidity. Function was assessed with the 1-leg hop test, in which patients were asked to perform a 1-leg hop for a specified distance on the index and normal sides. Three trials for each leg were recorded and averaged, and a ratio of the index knee to normal knee was calculated. Thigh atrophy was defined as the difference in thigh circumference between the involved and contralateral knees at 10 cm proximal to the superior pole of the patella. The Cybex 340 dynamometer (Cybex, New York, NY) was used to measure the difference in flexor and extensor muscle strength between the reconstructed and contralateral knees. Peak extension and flexion torques were isokinetically measured at 60°/s, 90°/s, and 180°/s. The side-to-side ratio (peak muscle torque of involved side/peak muscle torque of contralateral side ⫻ 100%) was used to measure thigh muscle strength. Anteroposterior and lateral weight-bearing radiographs were obtained preoperatively, annually after surgery, and at the final follow-up visit. The bone tunnels on the anteroposterior and lateral radiographs were measured by calipers at 3 months, at 2 years, and at the final follow-up. To evaluate bone tunnel enlargement, the sclerotic margins of the femoral and tibial tunnels were measured at the widest part of the tunnel. The measurements were corrected for radiographic magnification with a marker included on the films. Maximum tunnel widening during follow-up was compared with the initially drilled tunnel size. Six patients underwent MRI study. All of them had had reinjury of the operated knee during follow-up. The MRI study included transverse views of the femoral and tibial tunnels and a sagittal view of the knee for evaluating graft condition and graft– bone tunnel incorporation. Statistical Analysis The paired Student t test was used to compare preoperative and postoperative ligament laxity, thigh circumference, and extensor and flexor strength ratio. Comparison of the preoperative and postoperative Lysholm scores was made by use of a paired Student t test. The level of statistical significance is assumed at P ⬍ .05. RESULTS Associated Injury Detected During Surgery In this series significant non-ACL injuries were excluded, such as grade III medial collateral ligament injury, grade II or III posterior cruciate ligament in-
PERIOSTEUM-ENVELOPING HAMSTRING TENDON GRAFT TABLE 3.
Lysholm Knee Scores
Rating Excellent (95-100 points) Good (84-94 points) Fair (65-83 points) Poor (⬍65 points) Mean ⫾ SD*
Preoperatively
Final Follow-Up
0 0 68 (22%) 144 (78%) 56.4 ⫾ 10.2
193 (62%) 93 (30%) 18 (6%) 8 (2%) 94.5 ⫾ 8.4
NOTE. Data are presented as No. of patients (%), unless otherwise indicated. *P ⬍ .01, paired Student t test.
jury, and grade III lateral collateral or popliteal ligament complex injury. The most common injury associated with ACL tear was meniscus tear, which affected 197 patients (63%). Chondral injury was the second most commonly associated injury, affecting 60 patients (19%). Grade I or II medial collateral ligament tear, posteromedial/posterolateral injury, and grade I posterior cruciate ligament injury were also observed. These injuries affected 38 patients (12%), 21 patients (7%), and 18 patients (6%), respectively. Lysholm Knee Scores The median preoperative Lysholm knee score was 56 points (95% confidence interval, 45.2 to 76.6 points). At final follow-up, the median score was 95 points (95% confidence interval, 86.1 to 100 points) (P ⬍ .01) (Table 3). In total, 286 patients (92%) had good to excellent results, 18 (6%) had fair results, and 8 (2%) had poor results. IKDC Scores Activity: With regard to preinjury activity level, 259 patients participated in strenuous and moderate activities. After injury and before surgery, 259 (83%) were only able to participate in light or sedentary levels of activity. At the final postoperative follow-up, 257 patients (83%) were participating in moderate to strenuous activities (Table 2). Knee Function by Patient Subjective Assessment: Preoperative self-assessment, according to the IKDC subjective knee evaluation form, showed that the patients’ status was abnormal in 212 patients (68%) and severely abnormal in 100 (32%). At final follow-up assessment after reconstruction, 289 patients (93%) subjectively rated their knee function as normal or nearly normal. Symptoms: The symptom sections of the IKDC form assessed pain, swelling, and partial or complete giving way. Of the patients, 20 (6.4%) reported pain
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during moderate or strenuous activities and 18 (5.7%) reported swelling during moderate or strenuous activities. Moreover, 17 patients (5.4%) displayed symptoms of partial giving way during moderate or strenuous activities, and 3 (0.96%) reported occasions of full giving way during moderate or strenuous activities. Range of Motion: At the last follow-up, all patients could perform full knee extension, and 273 patients (87.5%) with differences in full flexion of 5° or less between the normal and reconstructed limbs were given a normal rating. The rating was nearly normal in 20 patients (6.4%) with 6° to 15° deficits in flexion, abnormal in 14 patients (4.5%) with 16° to 25° deficits in flexion, and severely abnormal in 5 patients (1.6%) with greater than 25° deficits in flexion (Table 4). Ligament Laxity: All patients received a KT-1000 arthrometer evaluation with 25° of flexion to preoperatively and postoperatively evaluate anterior displacement. Preoperatively, the mean anterior displacement was 11.70 ⫾ 1.86 mm. At final follow-up, KT-1000 examination showed 0 to 2 mm of anterior translation in 271 patients (86.9%), 3 to 5 mm of anterior laxity in 25 (8%), and more than 5 mm of translation in 16 (5.1%). The differences are measured as side-to-side differences. The mean anterior displacement at final follow-up was 1.62 ⫾ 1.58 mm. There was a significant difference between preoperative and postoperative evaluation (P ⬍ .01) (Table 5). Patellofemoral Crepitus: Patellofemoral crepitus with mild discomfort was noted in 16 patients, and
TABLE 4. Normal
IKDC Scores Nearly Severely Normal Abnormal Abnormal
Category Knee function 255 Symptoms 252 Pain 255 Swelling 259 Partial giving way 260 Full giving way 296 ROM 273 Ligament laxity 256 Patellofemoral crepitus 268 Donor site 295 Radiograph 282 Functional test 263 Final rating 249 (80%) 40
40 40 37 35 35 13 20 40
16 16 16 15 13 2 14 10
21 16 13 3 18 11 30 15 (13%) 16 (5%)
NOTE. Data are presented as No. of patients.
1 4 4 3 4 1 5 6 7 1 1 4 7 (2%)
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TABLE 5.
KT-1000 Evaluation of Anterior Knee Laxity Preoperatively Postoperatively
Anterior drawer test Grade I (0-5 mm) 0 Grade II (6-10 mm) 0 Grade III (11-15 mm) 274 (88%) Grade IV (⬎15 mm) 38 (12%) KT-1000 test for IKDC rating Normal (0-2 mm) 0 Nearly normal (3-5 mm) 0 Abnormal (6-10 mm) 0 Severely abnormal (⬎10 mm) 312 Mean ⫾ SD* 11.70 ⫾ 1.86
296 (94.9%) 10 (3.2%) 6 (1.9%) 0 271 (86.9%) 25 (8%) 10 (3.2%) 6 (1.9%) 1.62 ⫾ 1.58
NOTE. Data are presented as No. of patients (%), unless otherwise indicated. *P ⬍ .01 (paired Student t test) for comparison between preoperative and postoperative examination.
patellofemoral crepitus with moderate or severe pain on squatting occurred in 7 patients. Donor-site morbidity: There were 42 patients who had a minor hematoma over the periosteum harvest site for about 2 to 3 weeks, and the hematoma had resolved gradually without any subsequent procedure. No residual discomfort at the donor site was reported in 304 patients (97.5%). However, 8 patients (2.5%) had some tenderness, numbness, or irritation over the incision area. Radiographic Findings: Normal radiography in the joint space was noted in 263 patients (84.29%). Minimal radiologic deterioration on radiography at the final examination was found in 18 patients (5.7%), and joint space narrowing (2 to 4 mm wide) was observed in 11 patients (3.5%). One patient had significant medial joint space narrowing measuring greater than 4 mm. Functional Test: On functional testing with a 1-leg hop of the injured leg, 255 patients (81.7%) achieved a distance of 90% or more of that achieved with the normal leg, 40 patients (12.8%) achieved a distance of 76% to 89% of the normal leg, and 17 patients (5.5%) achieved hops of less than 70% of the distance. TABLE 6.
Overall Rating: The overall rating according to IKDC criteria was normal in 249 patients (80%), nearly normal in 40 (12.8%), abnormal in 16 (5%), and severely abnormal in 7 (2%) (Table 4). Thigh Muscle Atrophy and Muscle Strength Measurement of thigh circumference showed that 253 patients (81%) had a difference of less than 10 mm between their reconstructed and normal limbs whereas 44 patients had a difference of more than 10 mm. The Cybex study showed that 249 patients (80%) achieved extensor muscle strength in the reconstructed knee at 90% or more of normal knee strength and 47 patients (15%) recovered 80% to 90% of normal knee strength. Moreover, 234 patients (75%) achieved 90% or more of flexor muscle strength in the reconstructed knee, and 53 patients (17%) recovered 80% to 90% of normal knee strength. A statistically significant difference existed in thigh girth difference, extensor strength ratio, and flexor strength ratio before and after reconstruction after a minimum 2 years of follow-up (Table 6). Tunnel Enlargement At final follow-up, radiographs showed minimal bone tunnel widening. Assessment of overall tunnel enlargement showed bone tunnel enlargement of more than 1 mm in 5.4% of femoral tunnels and 6.1% of tibial tunnels (Fig 5). On MRI study in the 6 patients who had had reinjury of the operated knee, the tendon graft condition was tight and the incorporation between tendon graft and bone tunnel was good. Minimal tunnel widening was noted, and there was no fluid in the tunnel based on T2-weighted magnetic resonance images (Fig 6). Complications Eight patients had mild abscess at the suture sight; all recovered after suture removal. Ten patients complained about numbness over the tibial skin incision. Of these, 6 had nearly recovered after 6 months and 4
Difference in Thigh Muscle Atrophy, Flexor Muscle Strength, and Extensor Muscle Strength
Thigh Muscle Parameters Thigh girth difference Extensor strength ratio Flexor strength ratio
Preoperatively/Final Follow-Up (Mean ⫾ SD) (mm)
P Value*
17.07 ⫾ 6.58/8.81 ⫾ 6.42 77.92 ⫾ 9.12/90.07 ⫾ 9.81 80.18 ⫾ 11.72/90.21 ⫾ 11.22
⬍.01 ⬍.01 ⬍.01
*Comparison between preoperative and final follow-up examination by paired Student t test.
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FIGURE 5. Anteroposterior and lateral weight-bearing radiographs showed no tunnel expansion at final follow-up.
have residual numbness. Complete ACL rerupture was noted in 3 patients, and partial tear was noted in 4 patients. All of them had had reinjury of the knee. DISCUSSION ACL reconstruction surgery is a well-established technique, and the overall results are satisfactory, with IKDC and Lysholm scores greater than 88 points.3-6 Recently, many studies have focused on tunnel expansion after ACL reconstruction with hamstring autografts. Tunnel expansion has been a major concern after ACL reconstruction with hamstring tendon autografts. The possible causes of tunnel widening have been discussed, such as tunnel position,13 position of the fixation sites and type of fixation device,14,15 and timing of rehabilitation.10,11 Tunnel expansion is significant because of the greater distance from the normal insertion site and the biomechanical point of action of the ACL. Iorio et al.13 found that an anatomic surgical technique and a less aggressive rehabilitation process influenced the amount of tunnel enlargement after ACL reconstruction. The increased distance creates a potentially larger force moment during graft cycling, which may lead to greater bone tunnel expansion.13 The fixation methods also influence the rate of tunnel expansion. Fauno and Kaalund14 found that there was a significant reduction in tunnel widening in both the femur and the tibia when fixation points were close to the joint compared with systems where the fixation points were further apart.
Baumfeld et al.15 found that the EndoButton suspensory fixation system (Ethicon) had significantly more tunnel expansion compared with double– cross pin fixation within the tunnel. Early and aggressive rehabilitation also leads to tunnel expansion. Hantes et al.11 studied about brace-free, unrestricted ROM and full weight bearing in one group and restricted ROM and partial weight bearing in another group. They found that early motion increased the bone tunnel enlargement. Vadala et al.10 agreed with the conclusion that an accelerated, brace-free rehabilitation protocol can increase the bone tunnel enlargement. Micromotion of tendon graft in bone tunnel may be the leading cause contributing to tunnel widening. In a study by Rodeo et al.,12 osteoclasts were found at the tunnel aperture, and they noted that the graft tunnel may impair early graft incorporation and may lead to osteoclast-mediated bone resorption. Incorporation of tendon and bone is a major concern when performing ACL reconstruction, which may be compromised by tunnel expansion. However, the clinical results are not influenced by tunnel expansion based on current evidence,14,15,24 whereas laxity of the tendon graft and difficulties with revision are of concern. The periosteum consists of multipotent mesodermal cells that are capable of differentiating into various types of connective tissue and bone.16,25 Histologic examination of the periosteum showed the presence of an outer “fibrous layer” and an inner “cambium layer.” The fibrous layer contains fibroblasts, and the cambium layer contains progenitor cells.16 By attach-
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FIGURE 6. On MRI, the tendon graft condition was tight and the incorporation between tendon graft and 1 tunnel was good. Minimal tunnel widening was noted, and there was no fluid in the tunnel based on T2weighted magnetic resonance images.
ing the periosteum onto the tendon-bone interface, the fibroblasts in the fibrous layer could develop into scar tissue that contains collagen fibers that hold the tendon part, and the progenitor cells in the cambium layer can differentiate into osteoblasts and chondroblasts and subsequently into fibrocartilage and calcified fibrocartilage. The progenitor cells in the cambium layer of the periosteum can facilitate bony ingrowth into the collagenous tissue formed by the fibroblasts in the fibrous layer of the periosteum and can induce ossification and bone formation.25 In 1930 Burman and Umansky26 found that a free periosteal transplant wrapped around a tendon could generate bony ingrowth in the tendon as early as 2 weeks after surgery. In a rabbit model the periosteum was applied to tendon grafts by enveloping the tendon in a bone tunnel.19,20 Histologic examination showed that bony ingrowth into the cambium layer appeared at 4 weeks and that interdigitation occurred between the perios-
teum tissue and the tendon. The fibrous layer from the wrapped periosteum progressively became a collagen fiber– bone intermixture with anchorage, and incorporation and organization on the interface developed with time. Biomechanical testing showed a progressive increase in tendon pullout strength followed by bony ingrowth, mineralization, and incorporation of the healing tissue in the periosteum group. It also showed that there was a significant increase in the interface strength between the periosteum and control groups at 8 and 12 weeks. It appears that periosteum offers a powerful inductive ability between the tendon and the bone tunnel to incorporate healing. Our previous clinical study in 1998 showed that the use of hamstring tendon grafts without periosteum in ACL reconstruction resulted in enlargement of more than 1 mm in 19% of femoral tunnels and 12% of tibial tunnels.22 The overall IKDC rating was normal or nearly normal in 88% of patients.22 For better
PERIOSTEUM-ENVELOPING HAMSTRING TENDON GRAFT clinical results, with less tunnel expansion, and on the basis of these studies, we considered the periosteum potentially useful for stimulating and enhancing healing at the tendon-bone interface so that a satisfactory clinical result could be expected. We applied this concept to ACL reconstruction to enhance tendonbone healing by using autologous periosteum with the cambium layer facing toward the tunnel wall. Our previous study on the clinical outcome of using a hamstring tendon graft for ACL reconstruction showed that the overall IKDC rating was normal or nearly normal in 92% of patients. Furthermore, the overall 100-point subjective knee score was 94, and 7% of patients had grade 2 or greater ligament laxity.21 Better clinical results and less tunnel expansion could be achieved with this technique. Siebold et al.7 tried to determine whether a stepped router could reduce the postoperative tunnel expansion, and they found that there was no difference in tunnel expansion between extraction versus compaction drilling. On the basis of their study, the possible reason that our series had less tunnel expansion is not the compaction drilling. Fauno and Kaalund14 and Baumfeld et al.15 compared transfemoral fixation (TransFix; Arthrex Inc., Naples, FL) and interference screws (Arthrex) with extracortical fixation (EndoButton, Smith & Nephew, Memphis, TN) regarding tunnel expansion. They found that the suspensory fixation (EndoButton) had greater tunnel expansion, although the clinical results were similar within 2 years of follow-up. Our femoral fixation type in this series was Mersilene tape tied rigidly to the surface of the femoral cortex with a washer, and it is similar to EndoButton fixation, a suspensory fixation. Tunnel expansion was much less in our series; even we use the suspensory fixation type, which was proved having greater tunnel expansion by Fauno and Kaalund and Baumfeld et al. The difference between our series and those of Fauno and Kaalund and Baumfeld et al. is that we added periosteum where the graft approached the tunnel opening. The periosteum inside the femoral and tibial tunnel approaching the tunnel opening could accelerate the tendon-bone incorporation, decrease the micromotion of tendon graft due to plugging effect, and prevent synovial fluid influx. In their study Clatworthy et al.27 indicated that synovial fluid may influx between the tendon and bone tunnel and may impair tendon-bone healing and cause micromotion of the tendon-bone interface, possibly inducing osteolysis and eventual radiographic evidence of tunnel enlargement. In our series periosteum may have acted to seal the intraarticular tunnel opening in the early period to avoid
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synovial fluid influx between the tendon and the bone. Undesirable tendon motion in the tunnel and synovial fluid influx that may result in tunnel expansion can be avoided. Robert and Es-Sayeh28 studied 2 groups with and without a periosteal flap over the femoral tunnel, and they found that there was a significant reduction in tunnel enlargement with the periosteal flap, which is compatible with our results. Vadala et al.10 and Hantes et al.11 found less tunnel expansion in the conservatively treated group with partial weight bearing and restricted ROM. In contrast, in our series, we allowed full weight bearing on the second postoperative day and gradually increased ROM until full ROM was allowed at 8 weeks. Our result regarding tunnel expansion was much lesser, and it may have been caused by the effect of periosteum. Simonian et al.29 found that tunnel enlargement usually could be measured during the initial 3 months of followup, which should remind us that early protection of the operated knee is needed. In total 6 patients in our study had had reinjury of the operated knee during follow-up and underwent MRI study. On the MRI study, we could evaluate the tightness of the tendon graft and observe the incorporation of tendon and bone by examining the bone tunnel, to determine whether there was fluid with soft tissue content in the bone tunnel. In our patients the tendon graft condition was tight and the incorporation between tendon graft and bone tunnel was good without fluid in the tunnels based on T2-weighted magnetic resonance images. There was no soft tissue noted in the bone tunnel at the tendon-bone junction, which means that there was no fibrous tendon insertion and the tendon-bone healing was good. If we consider the tunnel expansion to be related to tendon graft loosening or reinjury to be related to tendon graft tear or laxity, MRI is a good tool to evaluate the tendon condition and tendon-bone incorporation. On the basis of animal studies, previous clinical studies of other authors, and our present clinical follow-up, we suggest that the addition of periosteum may decrease tunnel widening when used in hamstring ACL reconstruction with suspensory fixation. In this series tunnel enlargement of more than 1 mm was identified in only 5.4% of femoral tunnels and 6.1% of tibial tunnels. A previous clinical study in 2004 showed that bone tunnel enlargement of more than 1 mm was identified in 5% of femoral tunnels and 6% of tibial tunnels.21 In clinical practice the periosteum-enveloping technique was applied to ACL reconstruction with hamstring tendon grafts, and a satisfactory clinical result was achieved. Periosteum is easy to harvest from the proximal tibia through a routine incision for hamstring tendon har-
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vesting, and it takes approximately 3 more minutes to harvest. After tendon graft was well prepared, it took about 5 more minutes to suture the periosteum onto the tendon graft. The limitations of this study include that this is a case-series study, so there is no comparison group treated without periosteum. We could not compare the clinical difference in ACL reconstruction with and without periosteum. There was also a lack of comparison between “aggressive” and “nonaggressive” rehabilitation protocols for evaluation of the effect of periosteal flap. Biomechanical studies are also needed to evaluate whether the periosteum can make the tendon-bone incorporation stronger. Regarding tunnel expansion, there is no evidence that tunnel widening could impair the clinical result of ACL reconstruction. The maximum follow-up time is 7 years, and a longterm follow-up study may be needed in the future to evaluate the correlation between clinical outcome and imaging studies.
8. 9.
10.
11.
12.
13. 14.
CONCLUSIONS The study shows that satisfactory results can be achieved with the periosteum-enveloping hamstring tendon graft in single-bundle ACL reconstruction with minimal tunnel widening. Bone tunnel enlargement of more than 1 mm was identified in 5.4% of femoral tunnels and 6.1% of tibial tunnels, which was less than in other studies using comparable fixation. REFERENCES
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16. 17. 18. 19.
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28. Robert H, Es-Sayeh J. The role of periosteal flap in the prevention of femoral widening in anterior cruciate ligament reconstruction using hamstring tendons. Knee Surg Sports Traumatol Arthrosc 2004;12:30-35. 29. Simonian PT, Erickson MS, Larson RV, O’Kane JW. Tunnel expansion after hamstring anterior cruciate ligament reconstruction with 1-incision EndoButton femoral fixation. Arthroscopy 2000;16:707-714.