- Email: [email protected]
Distal femoral osteotomy for valgus arthritic knees
J Orthop Sci (2012) 17:745–749 DOI 10.1007/s00776-012-0273-1
ORIGINAL ARTICLE
Distal femoral osteotomy for valgus arthritic knees Rafael Thein • Shlomo Bronak • Ran Thein Barak Haviv
•
Received: 14 March 2012 / Accepted: 13 July 2012 / Published online: 7 August 2012 Ó The Japanese Orthopaedic Association 2012
Abstract Background Patients with genu valgum and isolated osteoarthritis of the lateral compartment are candidates for distal femoral varus osteotomy. Opening wedge osteotomy is a precise method to realign the knee axis with good short to midterm results. The aim of this study was to evaluate the outcome of patients who have had opening wedge distal femoral varus osteotomy utilizing the Puddu plate (Arthrex, Naples, FL, USA) fixation. Methods The study included 6 patients (7 knees) followed for an average of 6.5 ± 1.5 years after distal femoral varus osteotomy with Puddu fixation and iliac crest allograft. Clinical outcome was assessed by the Oxford Knee Score and subjective satisfaction rating. Pre- and postoperative radiographs were evaluated for tibiofemoral angle, Insall-Salvati index and Kellgren-Lawrence Grading Scale for osteoarthritis. Results The mean age at surgery was 46.7 ± 10.7 years. The mean body mass index at surgery was 29.6 ± 5.6 kg/m2. Overall at the last follow-up the mean Oxford Knee Score improved from 13.1 ± 8.6 to 26 ± 12.5. The average subjective satisfaction rate at the last follow-up was 6.6 ± 2.8. The measured tibiofemoral angle was corrected
Rafael Thein S. Bronak B. Haviv (&) Arthroscopy and Sports Injuries Unit, Hasharon Hospital, Rabin Medical Center, 7 Keren Kayemet St, 49372 Petach-Tikva, Israel e-mail: [email protected] Rafael Thein B. Haviv Orthopedic Department, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel Ran Thein Department of Orthopedics, Sheba Medical Center, Tel-Hashomer, Israel
by an average of 11.9°. There was no worsening of arthritic changes in comparison to the preoperational radiographs. All radiographs showed full incorporation of the bone grafts, and there were no hardware failures. At the end of this study none of the patients required additional surgery, and none had knee replacement. Conclusions Opening wedge distal femoral varus osteotomy with Puddu plate fixation can be a reliable procedure for the treatment of lateral compartment osteoarthritis of the knee associated with valgus deformity.
Introduction Distal femoral varus osteotomy (DFVO) can be offered to compliant patients with valgus knees who suffer from limited lateral compartment arthritis and are willing to cooperate with the long rehabilitation process [1]. Ideally, a joint-preserving surgery such as DFVO would be favored over a jointreplacing procedure. However, since the failure rate of DFVO can reach 50 % at 15 years [2], it is mainly indicated to avoid replacement in young patients. Moreover, valgus arthritis is less frequently encountered than varus arthritis. Thus, the number of candidates for DFVO and the clinical reports on this procedure are few. Wang and Hsu [3] followed 30 patients after DFVO with blade-plate fixation for an average of 99 months and found satisfactory results in 83 % of the patients. Backstein et al. [4] reviewed 40 patients with an average of 123 months and reported on good to excellent results in 60 % of the patients and a 10-year osteotomy survival rate of 82 %. Opening and closing wedge distal femoral osteotomies are the two main surgical options. The opening wedge is a good choice for medium or large corrections and is particularly easy and precise; however, for minimal deformity the closing wedge will heal faster and
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with a shorter recovery time. For opening wedge osteotomy, Puddu et al. [1] developed a method of fixation by special plates with spacers that helps prevent secondary loss of correction and shortening of the limb. In his series of the 21 patients followed for up to 14 years, clinical improvement was observed in all of the participants. In concordance with previous reports, this study hypothesis was that DFVO for selected patients has good clinical and radiographic results. The purpose of this study was to evaluate the outcome of patients with symptomatic lateral compartment osteoarthritis and genu valgum who have had opening wedge DFVO.
Materials and methods Patients included in this study were under the age of 65 years with isolated osteoarthritis (OA) of the lateral compartment, genu valgum (tibiofemoral angle [12°), good range of motion (i.e., flexion [90° and flexion contracture \10°) and without ligamentous instability. The indication for surgery was knee pain due to evident OA on examination and standing radiographs, not responsive to non-operative treatment for at least 1 year. Informed consent was obtained from all patients. Preoperative planning was made using radiographs of the lower limb with the patient standing. Pre-and postoperative radiographs were evaluated for tibiofemoral angle [5], Insall-Salvati index [6] and Kellgren-Lawrence Grading Scale [7] for osteoarthritis. All procedures in this series were performed by the senior author. An open-wedge varus osteotomy was performed in all patients, and a Puddu plate was used for internal fixation. The plates were from the first generation of the ‘Femoral Opening Wedge Osteotomy System’ by Arthrex and were not of the locking type. We aimed to shift the tibiofemoral angle to a degree that would place the mechanical axis at the middle of the knee (Fig. 1). This was achieved by calculating the desired correction to a neutral tibiofemoral angle, and intraoperatively a special guide rod was used to validate a neutral mechanical axis before choosing the plate. Surgical technique In general patients were operated on according to the technique previously described by Puddu et al. [1] utilizing the Puddu plate (Arthrex, Naples, FL, USA). The surgery was performed in the supine position under general anesthesia. An arthroscopic evaluation and treatment of intraarticular pathologies were undertaken prior to the osteotomy. Patients with advanced arthritis (i.e., more than grade 1 according to the ICRS classification [8]) of the medial compartment during arthroscopy were considered unsuitable for osteotomy.
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Fig. 1 Weight-bearing anteroposterior view radiographs of the right knee showing preoperative valgus with lateral compartment osteoarthritis (a) and at 6 years after distal femoral varus osteotomy (b)
We used the lateral approach to the distal femur. With the knee in extension and under fluoroscopic control, a guide pin (Steinmann) was drilled freehand from the near to the far cortex. This was obliquely oriented, starting approximately 4 cm proximal and directed to 1 cm from the level of the joint line. The osteotomy assembly was then mounted on the guide wire. Afterwards, a second pin was introduced at an appropriate angle up to the far cortex. The osteotomy apparatus was removed. An oscillating saw was used to perform an uncompleted cut precisely under the guide wire up to 2 cm away from the far cortex, which will serve as a hinge. Then a sharp osteotome was used to finish the osteotomy under fluoroscopic control, making certain that all the cancellous metaphyses are completely interrupted, but preserving a far hinge of approximately 0.5 cm of intact bone. The wedge opener was introduced and slowly advanced until the osteotomy was opened to obtain the planned realignment of the knee. The surgeon measured the dimension of the bone gap directly on the graduated tines of the wedge opener (i.e., 1 mm was equivalent to 18 of axis correction) and chose the plate. The plate could then be changed as needed after measuring the mechanical axis with a special guide rod. The plate was then fixed with two distal and four proximal screws. Finally, the wedge gap was filled with tricortical iliac crest allografts. The grafts were press-fit introduced to fill the defect, and the correct position of the plate and grafts was confirmed with anteroposterior and lateral radiographs. After the closure of the layers and placement of a drain, the patient’s knee was put into a hinged immobilizer. Rehabilitation Postoperative rehabilitation included immediate active movement and physiotherapy. A non-weight-bearing regimen was prescribed for 6 weeks. Soon after the operation,
Osteotomy for valgus knees
the patient started isometric quadriceps exercises and used a CPM (continuous passive motion) device to facilitate the range of motion. CPM was used for 2–3 weeks. The patient was rehabilitated with gradual increments of quadriceps muscle and hamstring-strengthening exercises. Knee radiographs were taken at 6 weeks postoperatively to observe graft incorporation, and if needed, the patient was ambulated with a knee-hinged immobilizer and partial weight bearing for another 6 weeks. Knee radiographs were taken again at 12 weeks postoperatively to verify signs of union in order to allow full weight bearing. None of the patients had delayed or non-union. Follow-up All patients were followed up at 2 weeks, 6 weeks, 3 months, 6 months and annually thereafter for radiological and clinical assessment. Clinical assessment was performed prospectively by an independent observer and included an interview, subjective satisfaction rating, Oxford Knee Score, physical examination and standing radiographs. The Oxford Knee Score is one of the rating scales for patients with degenerative disorders of the knee [9]. It comprised 12 multiple-choice questions, each with 5 responses. It was tested in patients undergoing total knee arthroplasty and was found to be reliable, valid and responsive [10]. Radiographs were evaluated for tibiofemoral angle, Insall-Salvati index and Kellgren-Lawrence Grading Scale for osteoarthritis. Statistics Results were expressed by descriptive methods (mean ± standard deviation). Student’s t test was used to compare paired samples (i.e., clinical scores and radiographic measurements). The outcome score was modeled as a function of age, body mass index (BMI) and radiographic findings with the use of multivariate regression analysis. A p value B0.05 was considered statistically significant.
Results From 2002 to 2006, only nine patients were candidates for distal femoral varus osteotomies (DFVO). Three were found to have significant arthritis of the medial compartment at the initial arthroscopy and therefore were excluded. Overall, six patients (one man, five women) who underwent DFVO were included in the study. All were operated on by a single surgeon (the senior author). Demographic data are presented in Table 1. All patients were relatively young, active patients. Specifically, there were one student,
747 Table 1 Preoperative data of patients who underwent openingwedge distal femoral osteotomy Patients (knees)
6 (7)
Men:women
1:5
Right:left
6:1 (1 bilateral)
Age
46.7 ± 10.7 years
Body mass index
29.6 ± 5.6 kg/m2
three secretaries, one driver, one carpenter and one nurse. Four of the patients participated in recreational sports (walking, swimming), and two did not. One patient was involved in a worker’s compensation injury. The mean duration of pain and disability before surgery was 10 ± 8 years. Patients were offered surgery if they had a valgus knee deformity (tibiofemoral angle [12°) and their knee symptoms persisted despite conservative treatment. Most patients were otherwise healthy except one who had diabetes (non-insulin dependent) and one with ischemic heart disease. One patient was a smoker. All patients had prolonged symptoms, and five of the seven knees had prior arthroscopic partial lateral menisectomies (between 1 to 10 years before the osteotomy). At the time of the index operation (i.e., on arthroscopic evaluation before osteotomy), one required partial lateral menisectomy because of a re-tear, and all had diffuse chondral lesions of the lateral compartment not amenable to microfracture, mosaicplasty or autologous chondrocyte implantation (ACI). These lesions were carefully probed, and any unstable edges were debrided. The mean follow-up time was 6.5 ± 1.5 years. Overall at the last follow-up the mean Oxford Knee Score improved from 13.1 ± 8.6 to 26 ± 12.5 (Table 2). In four out of seven knees, scores were rated as good, two as fair and one as poor. The average subjective satisfaction rate at the last follow-up was 6.6 ± 2.8 points on a scale of 0–10. Three patients were relatively dissatisfied with the surgery in terms of pain and disability. One was a 58-year-old patient (fair result), the second was involved in a worker’s compensation case (fair result), and the third had bilateral surgery and was dissatisfied with the second osteotomy (poor result). The radiographic findings are presented in Table 2. The medial compartment was unremarkable, and there was no worsening of lateral compartment arthritic changes in comparison to the preoperational radiographs. All radiographs showed full incorporation of the bone grafts, and there were no hardware failures. There was no significant correlation found among age, BMI and radiographic findings to the outcome scores. This is attributed to the small number of patients. Patients were discharged at postoperative day 3. No patient required a blood transfusion. There were no major
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Table 2 Pre- and postoperative knee score and radiological measurements (mean ± SD) Preoperative
Postoperative
p value
Oxford Knee Score
13.1 ± 8.6
26 ± 12.5
0.001
Tibiofemoral angle
13.5 ± 4.1 (genu valgum)
1.6 ± 2.1 (genu valgum)
0.003
Insall–Salvati index
1.1 ± 0.1
1.1 ± 0.1
\0.001
Kellgren–Lawrence grading (I, II, III, IV) of the lateral compartment
(1, 3, 3, 0)
(1, 3, 3, 0)
complications, specifically no infections, fractures or thromboembolic events. At the end of this study, none of the patients required additional surgery, and none had knee replacement.
Discussion Distal femoral varus osteotomy (DFVO) is not a common procedure even in major orthopedic centers. The reports on DFVO in the literature are few [11] because of the narrow range of indications. Hence, out of 1652 knee arthroscopic surgeries done at our institution over the study period, only 7 DFVOs were performed. This study’s results suggest that distal femoral varus osteotomy (DFVO) for selected patients with lateral compartment arthritis and valgus deformity of the knee can improve pain and function. Earlier clinical studies on the outcome of DFVO have shown promising results [12–15]. This was also supported by two recent long-term studies utilizing the technique of closing wedge medial osteotomy and blade plate fixation. Wang and Hsu [3] followed 30 patients for an average period of 99 months. In their study, 25 patients (83 %) had a satisfactory result according to the Hospital for Special Surgery rating system. With conversion to total knee arthroplasty as the end point, the cumulative 10-year survival rate for all patients was 87 %. Backstein et al. [4] followed 38 patients for an average period of 123 months. At the last follow-up, 24 knees (60 %) had good or excellent results according to the Knee Society score. The 10-year survival rate of the DFVO was 82 %. The technique used in the current study was previously described by Puddu et al. [1, 16, 17]. It involves a laterally based opening wedge osteotomy fixed with a Puddu plate and filled with bone graft. In his series of 21 patients followed for 14 years, all patients improved according to the International Knee Committe Documentation Committee (IKDC) rating scale and the HSS system. In contrast to Puddu, Jacobi et al. [18] had abandoned the opening wedge technique based on the often slow healing of the osteotomy and frequent irritation owing to the plate. However, in their
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series the hardware was different (Tomofix plate, Synthes), and bone grafting was not always used. In the current study, we did not experience such problems. The unremarkable union at the osteotomy site in all patients of the current study is probably the result of bone grafting as part of the technique. Moreover, the Puddu method of fixation by special plates with spacers helps prevent secondary loss of correction and shortening of the limb. Comparable to the above-mentioned studies, the participants in this study were mostly relatively healthy, young (mean age 46.7 ± 10.7 years) and overweight women (mean BMI 29.6 ± 5.6 kg/m2) with valgus knees. The mean follow-up time was 6.5 ± 1.5 years. Overall, at the last follow-up, the mean Oxford Knee Score improved from 13.1 ± 8.6 to 26 ± 12.5 (p = 0.001), and the patients were generally satisfied with the results. Radiographs at the last follow-up did not show worsening of the arthritic changes or alterations in patellar height [19]. Despite an overall clinical improvement, there was one poor result in a patient that had a bilateral osteotomy (at 6 months’ time difference). She was very happy with the first operation but unhappy with the second. In addition, there were two other fair results, one in a 58-year-old patient (the oldest in this series) and the second in a patient that was involved in a worker’s compensation injury. The radiographic changes in these three patients showed good alignment, union and no worsening of arthritis. This study has several limitations. There was no control group, although all patients failed a long trial of conservative treatment. Due to the limited number of patients in this study, correlation between scores to different variables such as age, BMI and radiographic findings was not possible. In addition, although the midterm results were good, long-term results in earlier studies showed a considerable failure rate, and thus we are conducting a longer follow-up on these patients. Conflict of interest of interest.
The authors declare that they have no conflict
References 1. Puddu G, Cipolla M, Cerullo G, Franco V, Giannı` E. Which osteotomy for a valgus knee? Int Orthop. 2010;34:239–47. 2. Kosashvili Y, Safir O, Gross A, Morag G, Lakstein D, Backstein D. Distal femoral varus osteotomy for lateral osteoarthritis of the knee: a minimum ten-year follow-up. Int Orthop. 2010;34:249–54. 3. Wang J-W, Hsu C-C. Distal femoral varus osteotomy for osteoarthritis of the knee. J Bone Joint Surg Am. 2005;87:127. 4. Backstein D, Morag G, Hanna S, Safir O, Gross A. Long-term follow-up of distal femoral varus osteotomy of the knee. J Arthroplasty. 2007;22:2–6. 5. Huang T, Tseng K, Chen W, Lin RM, Wu J, Chen T. Preoperative tibiofemoral angle predicts survival of proximal tibia osteotomy. Clin Orthop Relat Res. 2005;432:188–95.
Osteotomy for valgus knees 6. Insall J, Salvati E. Patella position in the normal knee joint. Radiology. 1971;101:101–4. 7. Kellgren JH, Lawrence JS. Radiological assessment of osteoarthrosis. Ann Rheum Dis. 1957;16:494–502. 8. Brittberg M, Winalski CS. Evaluation of cartilage injuries and repair. J Bone Joint Surg Am. 2003;85:58–69. 9. Dawson J, Fitzpatrick R, Murray D, Carr A. Questionnaire on the perceptions of patients about total knee replacement. J Bone Joint Surg Br. 1998;80:63–9. 10. Marx RG. Knee rating scales. Arthroscopy. 2003;19:1103–8. 11. Brouwer RW, Raaij van TM, Bierma-Zeinstra SM, Verhagen AP, Jakma TS, Verhaar JA. Osteotomy for treating knee osteoarthritis. Cochrane Database Syst Rev. 2007;18:CD004019. 12. Edgerton BC, Mariani EM, Morrey BF. Distal femoral varus osteotomy for painful genu valgum. A five-to-11-year follow-up study. Clin Orthop. 1993;288:263–9. 13. Healy WL, Anglen JO, Wasilewski SA, Krackow KA. Distal femoral varus osteotomy. J Bone Joint Surg Am. 1988;70:102–9.
749 14. McDermott AG, Finklestein JA, Farine I, Boynton EL, MacIntosh DL, Gross A. Distal femoral varus osteotomy for valgus deformity of the knee. J Bone Joint Surg Am. 1988;70:110–6. 15. Finkelstein JA, Gross AE, Davis A. Varus osteotomy of the distal part of the femur: a survivorship analysis. J Bone Joint Surg Am. 1996;78:1348–52. 16. Franco V, Cipolla M, Gerullo G, Gianni E, Puddu G. Open wedge osteotomy of the distal femur in the valgus knee. Orthopade. 2004;33:185–92. 17. Puddu G, Cipolla M, Cerullo G, Franco V, Gianni E. Osteotomies: the surgical treatment of the valgus knee. Sports Med Arthrosc. 2007;15:15–22. 18. Jacobi M, Wahl P, Bouaicha S, Jakob RP, Gautier E. Distal femoral varus osteotomy: problems associated with the lateral open-wedge technique. Arch Orthop Trauma Surg. 2011;131:725–8. 19. Closkey RF, Windsor RE. Alterations in the patella after a high tibial or distal femoral osteotomy. Clin Orthop Relat Res. 2001;389:51–6.
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ORIGINAL ARTICLE
Distal femoral osteotomy for valgus arthritic knees Rafael Thein • Shlomo Bronak • Ran Thein Barak Haviv
•
Received: 14 March 2012 / Accepted: 13 July 2012 / Published online: 7 August 2012 Ó The Japanese Orthopaedic Association 2012
Abstract Background Patients with genu valgum and isolated osteoarthritis of the lateral compartment are candidates for distal femoral varus osteotomy. Opening wedge osteotomy is a precise method to realign the knee axis with good short to midterm results. The aim of this study was to evaluate the outcome of patients who have had opening wedge distal femoral varus osteotomy utilizing the Puddu plate (Arthrex, Naples, FL, USA) fixation. Methods The study included 6 patients (7 knees) followed for an average of 6.5 ± 1.5 years after distal femoral varus osteotomy with Puddu fixation and iliac crest allograft. Clinical outcome was assessed by the Oxford Knee Score and subjective satisfaction rating. Pre- and postoperative radiographs were evaluated for tibiofemoral angle, Insall-Salvati index and Kellgren-Lawrence Grading Scale for osteoarthritis. Results The mean age at surgery was 46.7 ± 10.7 years. The mean body mass index at surgery was 29.6 ± 5.6 kg/m2. Overall at the last follow-up the mean Oxford Knee Score improved from 13.1 ± 8.6 to 26 ± 12.5. The average subjective satisfaction rate at the last follow-up was 6.6 ± 2.8. The measured tibiofemoral angle was corrected
Rafael Thein S. Bronak B. Haviv (&) Arthroscopy and Sports Injuries Unit, Hasharon Hospital, Rabin Medical Center, 7 Keren Kayemet St, 49372 Petach-Tikva, Israel e-mail: [email protected] Rafael Thein B. Haviv Orthopedic Department, Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel Ran Thein Department of Orthopedics, Sheba Medical Center, Tel-Hashomer, Israel
by an average of 11.9°. There was no worsening of arthritic changes in comparison to the preoperational radiographs. All radiographs showed full incorporation of the bone grafts, and there were no hardware failures. At the end of this study none of the patients required additional surgery, and none had knee replacement. Conclusions Opening wedge distal femoral varus osteotomy with Puddu plate fixation can be a reliable procedure for the treatment of lateral compartment osteoarthritis of the knee associated with valgus deformity.
Introduction Distal femoral varus osteotomy (DFVO) can be offered to compliant patients with valgus knees who suffer from limited lateral compartment arthritis and are willing to cooperate with the long rehabilitation process [1]. Ideally, a joint-preserving surgery such as DFVO would be favored over a jointreplacing procedure. However, since the failure rate of DFVO can reach 50 % at 15 years [2], it is mainly indicated to avoid replacement in young patients. Moreover, valgus arthritis is less frequently encountered than varus arthritis. Thus, the number of candidates for DFVO and the clinical reports on this procedure are few. Wang and Hsu [3] followed 30 patients after DFVO with blade-plate fixation for an average of 99 months and found satisfactory results in 83 % of the patients. Backstein et al. [4] reviewed 40 patients with an average of 123 months and reported on good to excellent results in 60 % of the patients and a 10-year osteotomy survival rate of 82 %. Opening and closing wedge distal femoral osteotomies are the two main surgical options. The opening wedge is a good choice for medium or large corrections and is particularly easy and precise; however, for minimal deformity the closing wedge will heal faster and
123
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with a shorter recovery time. For opening wedge osteotomy, Puddu et al. [1] developed a method of fixation by special plates with spacers that helps prevent secondary loss of correction and shortening of the limb. In his series of the 21 patients followed for up to 14 years, clinical improvement was observed in all of the participants. In concordance with previous reports, this study hypothesis was that DFVO for selected patients has good clinical and radiographic results. The purpose of this study was to evaluate the outcome of patients with symptomatic lateral compartment osteoarthritis and genu valgum who have had opening wedge DFVO.
Materials and methods Patients included in this study were under the age of 65 years with isolated osteoarthritis (OA) of the lateral compartment, genu valgum (tibiofemoral angle [12°), good range of motion (i.e., flexion [90° and flexion contracture \10°) and without ligamentous instability. The indication for surgery was knee pain due to evident OA on examination and standing radiographs, not responsive to non-operative treatment for at least 1 year. Informed consent was obtained from all patients. Preoperative planning was made using radiographs of the lower limb with the patient standing. Pre-and postoperative radiographs were evaluated for tibiofemoral angle [5], Insall-Salvati index [6] and Kellgren-Lawrence Grading Scale [7] for osteoarthritis. All procedures in this series were performed by the senior author. An open-wedge varus osteotomy was performed in all patients, and a Puddu plate was used for internal fixation. The plates were from the first generation of the ‘Femoral Opening Wedge Osteotomy System’ by Arthrex and were not of the locking type. We aimed to shift the tibiofemoral angle to a degree that would place the mechanical axis at the middle of the knee (Fig. 1). This was achieved by calculating the desired correction to a neutral tibiofemoral angle, and intraoperatively a special guide rod was used to validate a neutral mechanical axis before choosing the plate. Surgical technique In general patients were operated on according to the technique previously described by Puddu et al. [1] utilizing the Puddu plate (Arthrex, Naples, FL, USA). The surgery was performed in the supine position under general anesthesia. An arthroscopic evaluation and treatment of intraarticular pathologies were undertaken prior to the osteotomy. Patients with advanced arthritis (i.e., more than grade 1 according to the ICRS classification [8]) of the medial compartment during arthroscopy were considered unsuitable for osteotomy.
123
Fig. 1 Weight-bearing anteroposterior view radiographs of the right knee showing preoperative valgus with lateral compartment osteoarthritis (a) and at 6 years after distal femoral varus osteotomy (b)
We used the lateral approach to the distal femur. With the knee in extension and under fluoroscopic control, a guide pin (Steinmann) was drilled freehand from the near to the far cortex. This was obliquely oriented, starting approximately 4 cm proximal and directed to 1 cm from the level of the joint line. The osteotomy assembly was then mounted on the guide wire. Afterwards, a second pin was introduced at an appropriate angle up to the far cortex. The osteotomy apparatus was removed. An oscillating saw was used to perform an uncompleted cut precisely under the guide wire up to 2 cm away from the far cortex, which will serve as a hinge. Then a sharp osteotome was used to finish the osteotomy under fluoroscopic control, making certain that all the cancellous metaphyses are completely interrupted, but preserving a far hinge of approximately 0.5 cm of intact bone. The wedge opener was introduced and slowly advanced until the osteotomy was opened to obtain the planned realignment of the knee. The surgeon measured the dimension of the bone gap directly on the graduated tines of the wedge opener (i.e., 1 mm was equivalent to 18 of axis correction) and chose the plate. The plate could then be changed as needed after measuring the mechanical axis with a special guide rod. The plate was then fixed with two distal and four proximal screws. Finally, the wedge gap was filled with tricortical iliac crest allografts. The grafts were press-fit introduced to fill the defect, and the correct position of the plate and grafts was confirmed with anteroposterior and lateral radiographs. After the closure of the layers and placement of a drain, the patient’s knee was put into a hinged immobilizer. Rehabilitation Postoperative rehabilitation included immediate active movement and physiotherapy. A non-weight-bearing regimen was prescribed for 6 weeks. Soon after the operation,
Osteotomy for valgus knees
the patient started isometric quadriceps exercises and used a CPM (continuous passive motion) device to facilitate the range of motion. CPM was used for 2–3 weeks. The patient was rehabilitated with gradual increments of quadriceps muscle and hamstring-strengthening exercises. Knee radiographs were taken at 6 weeks postoperatively to observe graft incorporation, and if needed, the patient was ambulated with a knee-hinged immobilizer and partial weight bearing for another 6 weeks. Knee radiographs were taken again at 12 weeks postoperatively to verify signs of union in order to allow full weight bearing. None of the patients had delayed or non-union. Follow-up All patients were followed up at 2 weeks, 6 weeks, 3 months, 6 months and annually thereafter for radiological and clinical assessment. Clinical assessment was performed prospectively by an independent observer and included an interview, subjective satisfaction rating, Oxford Knee Score, physical examination and standing radiographs. The Oxford Knee Score is one of the rating scales for patients with degenerative disorders of the knee [9]. It comprised 12 multiple-choice questions, each with 5 responses. It was tested in patients undergoing total knee arthroplasty and was found to be reliable, valid and responsive [10]. Radiographs were evaluated for tibiofemoral angle, Insall-Salvati index and Kellgren-Lawrence Grading Scale for osteoarthritis. Statistics Results were expressed by descriptive methods (mean ± standard deviation). Student’s t test was used to compare paired samples (i.e., clinical scores and radiographic measurements). The outcome score was modeled as a function of age, body mass index (BMI) and radiographic findings with the use of multivariate regression analysis. A p value B0.05 was considered statistically significant.
Results From 2002 to 2006, only nine patients were candidates for distal femoral varus osteotomies (DFVO). Three were found to have significant arthritis of the medial compartment at the initial arthroscopy and therefore were excluded. Overall, six patients (one man, five women) who underwent DFVO were included in the study. All were operated on by a single surgeon (the senior author). Demographic data are presented in Table 1. All patients were relatively young, active patients. Specifically, there were one student,
747 Table 1 Preoperative data of patients who underwent openingwedge distal femoral osteotomy Patients (knees)
6 (7)
Men:women
1:5
Right:left
6:1 (1 bilateral)
Age
46.7 ± 10.7 years
Body mass index
29.6 ± 5.6 kg/m2
three secretaries, one driver, one carpenter and one nurse. Four of the patients participated in recreational sports (walking, swimming), and two did not. One patient was involved in a worker’s compensation injury. The mean duration of pain and disability before surgery was 10 ± 8 years. Patients were offered surgery if they had a valgus knee deformity (tibiofemoral angle [12°) and their knee symptoms persisted despite conservative treatment. Most patients were otherwise healthy except one who had diabetes (non-insulin dependent) and one with ischemic heart disease. One patient was a smoker. All patients had prolonged symptoms, and five of the seven knees had prior arthroscopic partial lateral menisectomies (between 1 to 10 years before the osteotomy). At the time of the index operation (i.e., on arthroscopic evaluation before osteotomy), one required partial lateral menisectomy because of a re-tear, and all had diffuse chondral lesions of the lateral compartment not amenable to microfracture, mosaicplasty or autologous chondrocyte implantation (ACI). These lesions were carefully probed, and any unstable edges were debrided. The mean follow-up time was 6.5 ± 1.5 years. Overall at the last follow-up the mean Oxford Knee Score improved from 13.1 ± 8.6 to 26 ± 12.5 (Table 2). In four out of seven knees, scores were rated as good, two as fair and one as poor. The average subjective satisfaction rate at the last follow-up was 6.6 ± 2.8 points on a scale of 0–10. Three patients were relatively dissatisfied with the surgery in terms of pain and disability. One was a 58-year-old patient (fair result), the second was involved in a worker’s compensation case (fair result), and the third had bilateral surgery and was dissatisfied with the second osteotomy (poor result). The radiographic findings are presented in Table 2. The medial compartment was unremarkable, and there was no worsening of lateral compartment arthritic changes in comparison to the preoperational radiographs. All radiographs showed full incorporation of the bone grafts, and there were no hardware failures. There was no significant correlation found among age, BMI and radiographic findings to the outcome scores. This is attributed to the small number of patients. Patients were discharged at postoperative day 3. No patient required a blood transfusion. There were no major
123
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Table 2 Pre- and postoperative knee score and radiological measurements (mean ± SD) Preoperative
Postoperative
p value
Oxford Knee Score
13.1 ± 8.6
26 ± 12.5
0.001
Tibiofemoral angle
13.5 ± 4.1 (genu valgum)
1.6 ± 2.1 (genu valgum)
0.003
Insall–Salvati index
1.1 ± 0.1
1.1 ± 0.1
\0.001
Kellgren–Lawrence grading (I, II, III, IV) of the lateral compartment
(1, 3, 3, 0)
(1, 3, 3, 0)
complications, specifically no infections, fractures or thromboembolic events. At the end of this study, none of the patients required additional surgery, and none had knee replacement.
Discussion Distal femoral varus osteotomy (DFVO) is not a common procedure even in major orthopedic centers. The reports on DFVO in the literature are few [11] because of the narrow range of indications. Hence, out of 1652 knee arthroscopic surgeries done at our institution over the study period, only 7 DFVOs were performed. This study’s results suggest that distal femoral varus osteotomy (DFVO) for selected patients with lateral compartment arthritis and valgus deformity of the knee can improve pain and function. Earlier clinical studies on the outcome of DFVO have shown promising results [12–15]. This was also supported by two recent long-term studies utilizing the technique of closing wedge medial osteotomy and blade plate fixation. Wang and Hsu [3] followed 30 patients for an average period of 99 months. In their study, 25 patients (83 %) had a satisfactory result according to the Hospital for Special Surgery rating system. With conversion to total knee arthroplasty as the end point, the cumulative 10-year survival rate for all patients was 87 %. Backstein et al. [4] followed 38 patients for an average period of 123 months. At the last follow-up, 24 knees (60 %) had good or excellent results according to the Knee Society score. The 10-year survival rate of the DFVO was 82 %. The technique used in the current study was previously described by Puddu et al. [1, 16, 17]. It involves a laterally based opening wedge osteotomy fixed with a Puddu plate and filled with bone graft. In his series of 21 patients followed for 14 years, all patients improved according to the International Knee Committe Documentation Committee (IKDC) rating scale and the HSS system. In contrast to Puddu, Jacobi et al. [18] had abandoned the opening wedge technique based on the often slow healing of the osteotomy and frequent irritation owing to the plate. However, in their
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series the hardware was different (Tomofix plate, Synthes), and bone grafting was not always used. In the current study, we did not experience such problems. The unremarkable union at the osteotomy site in all patients of the current study is probably the result of bone grafting as part of the technique. Moreover, the Puddu method of fixation by special plates with spacers helps prevent secondary loss of correction and shortening of the limb. Comparable to the above-mentioned studies, the participants in this study were mostly relatively healthy, young (mean age 46.7 ± 10.7 years) and overweight women (mean BMI 29.6 ± 5.6 kg/m2) with valgus knees. The mean follow-up time was 6.5 ± 1.5 years. Overall, at the last follow-up, the mean Oxford Knee Score improved from 13.1 ± 8.6 to 26 ± 12.5 (p = 0.001), and the patients were generally satisfied with the results. Radiographs at the last follow-up did not show worsening of the arthritic changes or alterations in patellar height [19]. Despite an overall clinical improvement, there was one poor result in a patient that had a bilateral osteotomy (at 6 months’ time difference). She was very happy with the first operation but unhappy with the second. In addition, there were two other fair results, one in a 58-year-old patient (the oldest in this series) and the second in a patient that was involved in a worker’s compensation injury. The radiographic changes in these three patients showed good alignment, union and no worsening of arthritis. This study has several limitations. There was no control group, although all patients failed a long trial of conservative treatment. Due to the limited number of patients in this study, correlation between scores to different variables such as age, BMI and radiographic findings was not possible. In addition, although the midterm results were good, long-term results in earlier studies showed a considerable failure rate, and thus we are conducting a longer follow-up on these patients. Conflict of interest of interest.
The authors declare that they have no conflict
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