- Email: [email protected]
Saphenous Nerve
524
SECTION XXVII Complications
132
Numbness/Saphenous Nerve Tomoyuki Mochizuki, MD, PhD, Keiichi Akita, MD, PhD, Takeshi Muneta, MD, PhD
INTRODUCTION Leg numbness due to nerve damage is one of the considerable complications after anterior cruciate ligament (ACL) reconstruction using both bone–patellar tendon–bone (BPTB) and medial hamstring tendons. Such patients especially complain of uncomfortable feelings when falling on their knees. Harvesting a BPTB graft includes risks of damaging nerves and causing sensory disturbance.1,2 Pagnani et al.3 pointed out the risk of saphenous nerve damage by harvesting medial hamstring tendons in the region of the pes anserinus. Many authors have reported the nerve distribution patterns of the infrapatellar regions.2,4–12 It is well known that both the medial cutaneous nerve of the femoral nerve and the infrapatellar branch of the saphenous nerve are distributed throughout the infrapatellar region and the anterior lower leg region.9,10,12 The saphenous nerve descends laterally along the femoral artery and enters the adductor canal. It then leaves the artery at the distal end of the canal to proceed vertically along the medial side of the knee and runs between the sartorius and gracilis tendons. In contrast, the medial femoral cutaneous nerve originates from the anterior cutaneous branches of the femoral nerve. The medial femoral cutaneous nerve runs laterally to the femoral artery, and then it crosses anteriorly to the artery at the apex of the femoral triangle to be distributed to the anteromedial thigh and the infrapatellar region. Branches of the medial femoral cutaneous nerve and the infrapatellar branch of the saphenous nerve connect to each other9,10,12 and form the subsartorial plexus in the infrapatellar region.13
BONE–TENDON–BONE AUTOGRAFT Anterior knee pain including leg numbness has been reported as a main complication of ACL reconstruction using BPTB grafts. In previous reports, the rate of postoperative anterior knee pain ranged from 4% to more than 40%.8,14,15 Mishra et al. at first described a technique using two horizontal incisions for patellar tendon harvest for the purpose of more cosmetic scarring and reducing pain and flexion limitation.16 Kartus et al.17 used a technique with two vertical incisions and reported an insensitive area compared with the insensitive area that resulted from a traditional vertical incision, which averaged 24 cm. Tsuda et al.18 changed the method of approaching the retinaculum layer, opening it horizontally rather than splitting it to protect nerves using two horizontal incisions. They reported a 17% rate of postopera tive leg numbness. Portland et al.19 compared a horizontal incision and a vertical incision and reported an infrapatellar numbness of 43% resulting from a horizontal incision and 59% resulting from a horizontal incision.
HAMSTRING AUTOGRAFT The donor site morbidity associated with harvesting a hamstring tendon graft is well recognized to be less common than that associated with harvesting a BPTB autograft.20 However, sensory disturbance is frequently observed in regions on the anterior lower leg after ACL reconstruction using medial hamstring tendons.21–27 The incidence of sensory disturbance is reported
to range from 50% to 88%.22–27 Figueroa et al. reported that a hypoesthesia area was found in 77%, with an average area of 36 cm2.23 Kjærgaard et al. reported that the incidence of sensory disturbance did not change, but the area was decreased 1-year postoperatively in 46%. Inderhaug et al. performed a long-term evaluation and reported that sensory disturbance after hamstring tendon harvesting is probably permanent.27
CLINICAL EXAMINATION We clinically examined 103 patients who had arthroscopically assisted ACL reconstructions using medial hamstring tendons to investigate the frequencies and areas of sensory disturbance.28 As an operative procedure, we made two horizontal incisions for the arthroscopy portal and one longitudinal incision (2.5–3 cm) at the pes anserinus for the tendon harvest and the tibial drill holes. We performed an inside-out technique and used Endobutton (Smith & Nephew Endoscopy, Andover, Massachusetts) for femoral fixation. The clinical examination was performed for an average of 13 months (range 6–18 months) after the operation. We detected sensory disturbance on the anterior surface of the lower leg in 60 of 103 (58%) patients. We randomly selected 13 patients with sensory disturbance, and we neurologically examined in detail the regions of sensory disturbance. The regions of sensory disturbance were of various sizes and shapes (Fig. 132.1). These regions were generally quadrilateral and located lateral to the longitudinal incision for tendon harvest and distal to the horizontal incisions for the arthroscopy portal. In the detailed neurological examination, in 8 of 13 legs (62%) the region was very close to the longitudinal incision (see Fig. 132.1A–C), and in the other five legs (38%) it was relatively far away from the longitudinal incision (see Fig. 132.1D). The region was lower than the superior end of the longitudinal incisions in 12 of 13 legs (92%); however, in one leg (8%) the region was close to the horizontal incisions (see Fig. 132.1C). The region was located in the upper half of the lower leg in 10 legs (77%); however, in three legs (23%) the region was wider than others (see Fig. 132.1B).
ANATOMICAL INVESTIGATIONS In our anatomical study, 51 lower limbs of 26 adult cadavers were used.25 In the mediodistal region of the patella, the nerve branches pierced the fascia cruris in various patterns and ran on the outer surface of the fascia to supply the skin (Fig. 132.2). On the outer surface of the fascia, the nerve branches often were connected to each other. In the regions near the horizontal and longitudinal skin incision lines, the nerve branches ran on the outer surface of the fascia cruris in all legs. After complete removal of the fasciae lata and cruris, the origin of the nerve branches was examined. The anterior surface of the lower leg was innervated by branches of the medial femoral cutaneous nerve proximally and by branches of the saphenous nerve distally. In addition, the patellar region was innervated by branches of the intermediate femoral cutaneous nerve superiorly and by branches of the medial femoral cutaneous nerve medially and inferiorly. Compared with our clinical examinations, the
CHAPTER 132 Numbness/Saphenous Nerve
525
132 P
P
H
4 (31%)
A
3 (23%)
1 (8%)
B
P
C
P
Sa
Sv H
Fig. 132.2. Examples of the distribution of the nerve branches on the fasciae lata and cruris. The nerve branches connect in various manners in the medial infrapatellar region. Some nerve branches pass through the longitudinal skin incision line. H, Skin incision for harvest; P, horizontal skin incision for portal for arthroscopy; Sa, sartorius muscle; Sv, saphenous vein.
5 (38%)
D
Fig. 132.1. Examples of cases of sensory disturbance in 13 legs. A, 4 legs (31%); B, 3 legs (23%); C, 1 leg (8%); D, 5 legs (38%). P, Skin incision for arthroscopy portal; H, skin incision for tendon harvest.
sensory disturbance regions were considered to correspond with the regions supplied by the branches of the medial femoral cutaneous and saphenous nerves. In 33 of 51 legs (65%; Fig. 132.3A and B), the infrapatellar branch of the saphenous nerve ran along the inferoposterior border of the sartorius muscle. The infrapatellar branch of the saphenous nerve pierced the distal part of the sartorius muscle in 16 of 51 legs (31%; see Fig. 132.3C). In two legs (4%; see Fig. 132.3D), the branch of the saphenous nerve emerged from the anterosuperior border of the sartorius muscle and ran lateralward horizontally. The infrapatellar region and the anterior region of the lower leg were generally supplied by branches of both the medial femoral cutaneous nerve and the saphenous nerve in various patterns. Branches of the medial femoral cutaneous nerve were also distributed to the anterior surface of the leg in eight legs (16%; see Fig. 132.3A), and branches of the saphenous nerve were also observed to supply the infrapatellar region in two legs (4%; see Fig. 132.3D). Branches of these nerves and their connections were distributed to the region around the insertion of the sartorius muscle. At least, therefore, the branches of these two nerves showed a complementary distribution and a broad transitional zone. One or more branches of the nerve ran across the line of the longitudinal incision in 88% of the cases.
DISCUSSION In numerous clinical anatomical studies, nerve distribution patterns of the infrapatellar region have been discussed.2,4–8,10,29 The nerve branches supplying the skin of the medioinferior region of the patella are recognized as the infrapatellar branches of the saphenous nerve in most studies. However, according to our study and standard anatomy textbooks,13,16 branches of the saphenous nerve and the medial femoral cutaneous nerve, which originate from the anterior cutaneous branches of the femoral nerve, are distributed to this region. In addition, the branches of the medial femoral cutaneous nerve sometimes extend to the anterior lower leg region. Interestingly, although both nerves are clearly distinguishable in origin, it is very difficult to identify the border between their distribution territories due to their numerous connections, because of their complementary distribution. On the basis of the detailed clinical and anatomical investigations, the sensory disturbance is considered to be closely related to the skin incisions. Nerve injuries due to the incisions used for the arthroscopy portal, as well as the related anatomical findings, have been reported.2,11 In the present clinical findings, the sensory disturbance region was located in close proximity to
526
SECTION XXVII Complications In
Mn
In
8 (16%)
In
B
25 (49%)
Mn
In
C
16 (31%)
Mn
Sn
Sn
Sn
Sn
A
Mn
D
2 (4%)
Fig. 132.3. Four patterns of the distribution of the nerve branches based on the findings of 51 legs. A, Branches of the medial femoral cutaneous nerve are distributed to the anterior leg region (8 legs; 16%). B, Branches of the medial femoral cutaneous nerve are distributed to the infrapatellar region, and branches of the saphenous nerve are distributed to the anterior leg region (25 legs; 49%). C, The infrapatellar branch of the saphenous nerve pierces the sartorius muscle and is distributed to the infrapatellar region (16 legs; 31%). D, The infrapatellar branch of the saphenous nerve emerges from the anterior border of the sartorius muscle and is distributed to the infrapatellar region (2 legs; 4%). In, Intermediate femoral cutaneous nerve; Mn, medial femoral cutaneous nerve; Sn, saphenous nerve.
the arthroscopy portals in only one case (see Fig. 132.1C). The branch of the medial femoral cutaneous nerve might have been injured by the incisions for the arthroscopy portal. There have been few reports on nerve injuries related to the skin incision for tendon harvest.13 The line of skin incision for tendon harvest at the pes anserinus runs across the nerve branches originating from the medial femoral cutaneous nerve and the saphenous nerve. In some patients, the region of the sensory disturbance is not adjacent to the longitudinal skin incision (see Fig. 132.1D). These cases might be explained by the various patterns of the connections and the overlapping distribution territories of the saphenous nerve and the medial femoral cutaneous nerve. The possibility of nerve injury during harvesting of the semitendinosus tendon with a tendon stripper cannot be overlooked. Sanders et al. reported that the saphenous nerve is intimately involved with the gracilis tendon and likely predisposed to damage during passage of a tendon stripper. In our study,30 the main trunk of the saphenous nerve runs distally on the medial (outer) surfaces of the tendons of the gracilis and semitendinosus muscles along the medial collateral ligament. Because the sensory disturbance region was located lateral to the longitudinal incision line in all patients, the tendon harvest using a tendon stripper cannot be the main reason for the sensory disturbance. Injury or entrapment of the main trunk of the saphenous nerve has been reported,31,32 but the sensory disturbance region due to such injury is much wider than that found in our study. If the tendon stripper caused the nerve injury, the main trunk of the saphenous nerve could be damaged along with the branches of the nerve, as previously pointed out by Pagnani et al.3 Therefore it is very important to be careful with the main trunk of the saphenous nerve, due to its close positional relationship to the tendons, to avoid sensory disturbance after ACL reconstruction. The complicated anatomical variations of the nerve branches in the infrapatellar region and the anterior lower leg region preclude absolute avoidance in any surgical knee incision (Fig. 132.4). Ebrahein and Mekhail6 described a safety zone to avoid injury of the infrapatellar branch of the saphenous nerve. However, their zone must be supplied by the branches of the medial femoral cutaneous nerve. Therefore it might be very difficult to find a completely safe zone based on the findings of the present anatomical study.25 Nevertheless an oblique incision for the tendon harvest would be
P
P
X Sa
H
Y
Z
Fig. 132.4. Schematic drawings of the nervous distribution zone in the infrapatellar region and the anterior leg region. The infrapatellar region and the anterior lower leg region are divided into three areas based on the distribution of the nervous branches: X, the region distributed by the medial femoral cutaneous nerve; Y, the transitional zone between the regions X and Z; and Z, the region distributed by the saphenous nerve. H, Skin incision for tendon harvest; P, horizontal skin incision for portal for arthroscopy.
CHAPTER 133 Hardware Complications after Anterior Cruciate Ligament Reconstruction
a good candidate to minimize the area of the sensory disturbance to avoid cutting the courses of the various branches of the nerves, based on our findings of the nerve courses and distribution. Boon et al. also suggested a safe angle for harvesting tendons is 52.5 degrees in their anatomic study.33 SELECTED READINGS
Abram LJ, Froimson AI. Saphenous nerve injury. An unusual arthroscopic complication. Am J Sports Med. 1991;19:668–669. Bertnam C, Porsche M, Hackenbroch MH, Terhaag D. Saphenous neuralgia after arthroscopically assisted ACL reconstruction with a semitendinosus and gracilis tendon graft. Arthroscopy. 2000;16:763–766. Boon JM, Van Wyk MJ, Jordaan D. A safe area and angle for harvesting autogenous tendons for anterior cruciate ligament reconstruction. Surg Radiol Anat. 2004;26:167–171. Figueroa D, Calvo R, Vaisman A, Campero M, Moraga C. Injury to the infrapatellar branch of the saphenous nerve in ACL reconstruction with the hamstrings technique: clinical and electrophysiological study. Knee. 2008;15:360–363. Inderhaug E, Strand T, Solheim E. The impact of sensory deficits after harvesting hamstrings autograft for ACL reconstruction. Knee Surg Sports Traumatol Arthrosc. 2015;23:1060–1064. Kartus J, Ejerhed L, Sernert N, Brandsson S, Karlsson J. Comparison of traditional and subcutaneous patellar tendon harvest: a prospective study of donor site-related problems after ACL reconstruction using different graft harvesting techniques. Am J Sports Med. 2000;28:328–335.
133
527
Mochizuki T, Akita K, Muneta T, Sato T. Anatomical bases for minimizing sensory disturbance after arthroscopically-assisted anterior cruciate ligament reconstruction using medial hamstring tendons. Surg Radiol Anat. 2003;25:192–199. Papastergiou SG, Voulgaropoulos H, Mikalef P. Injuries to the infrapatellar branch(es) of the saphenous nerve in anterior cruciate ligament reconstruction with four-strand hamstring tendon autograft: vertical versus horizontal incision for harvest. Knee Surg Sports Traumatol Arthrosc. 2005;14:789–793. Portland GH, Martin D, Keene G, Menz T. Injury to the infrapatellar branch of the saphenous nerve in anterior cruciate ligament reconstruction: comparison of horizontal versus vertical harvest site incisions. Arthroscopy. 2005;3:281–285. Sanders B, Rolf R, McClelland W, Xerogeanes J. Prevalence of saphenous nerve injury after autogenous hamstring harvest: an anatomic and clinical study of sartorial branch injury. Arthroscopy. 2007;23:956–963. Tifford CD, Spero L, Luke T, Plancher KD. The relationship of the infrapatellar branches of the saphenous nerve to arthroscopy portals and incisions for ACL surgery: an anatomic study. Am J Sports Med. 2000;28:562–567.
A complete reference list can be found online at ExpertConsult.com.
Hardware Complications after Anterior Cruciate Ligament Reconstruction Robert Brophy, MD, Robert G. Marx, MD
INTRODUCTION A variety of autograft and allograft tissues can be used for reconstruction of the anterior cruciate ligament (ACL), and a number of different tools and techniques can be used to achieve graft fixation, whether bone to bone or tendon to bone. Commonly used fixation devices include interference screws (metallic and bioabsorbable), suspensory fixation (the Endobutton [Acufex Microsurgical, Mansfield, Massachusetts], RetroButton [Arthrex, Naples, Florida], ACL TightRope [Arthrex, Naples, Florida]), and cross-pins. Complications related to graft fixation are often specific to the type of fixation used, although a number of themes recur. We will review each type of fixation and the related intraoperative and postoperative complications, as well as methods for managing both types of complication. Obviously the ideal management is avoidance of the complication in the first place. Skeletally immature patients are susceptible to a unique set of complications regardless of the method of fixation, and we will review these separately.
INTERFERENCE SCREWS Interference screws are a widely used method of fixation during ACL reconstruction, both for bone-to-bone fixation and soft tissue–to–bone fixation. A number of complications related to interference screws may be encountered, and they can occur intraoperatively or postoperatively.
Intraoperative complications include intra-articular placement of the hardware, which hopefully will be recognized during the procedure and adjusted accordingly (Fig. 133.1). During insertion of the screw, possible complications include laceration of the graft passing suture,1 advancement of the graft within the bone tunnel,1 graft laceration1 and even rupture,2 fracture of the graft bone plug,3 and screw breakage.4–6 To minimize the risk of lacerating the passing suture, at least one suture can be passed through the tendon at the base of the bone plug.1 To minimize the risk of graft rupture, methylene blue can be used to mark the bone-tendon junction of the graft, the anterior portion of the bone tunnel can be notched to ease the initial engagement of the screw, the cancellous edge of the bone plug can be placed facing anterior flush with the intra-articular edge of the femoral tunnel, and a protective sheath or cannula can be used to protect the graft during screw placement.2 Another helpful technique to protect the graft is to insert the femoral screw over a guidewire drilled through a cannulated screwdriver. If the graft ruptures during screw placement, a number of salvage options may be used. If a patellar tendon graft is cut at the bone-tendon junction, the graft can be reversed, placing the intact bone plug in the femoral tunnel and fixing the tendinous portion of the graft through the tibial tunnel with a post or button.2,7 If there is insufficient graft length remaining, alternative autograft or allograft should be used. To minimize the chance of graft advancement, it is important to maintain constant tension
133
REFERENCES
1. Graf B, Uhr F. Complications of intra-articular anterior cruciate reconstruction. Clin Sports Med. 1988;7:835–848. 2. Mochida H, Kikuchi S. Injury to infrapatellar branch of saphenous nerve in arthroscopic knee surgery. Clin Orthop Relat Res. 1995;320:88–94. 3. Pagnani MJ, Warner JJP, O’Brien SJ, Warren RF. Anatomic considerations in harvesting the semitendinosus and gracilis tendons and a technique of harvest. Am J Sports Med. 1993;21:565–571. 4. Arthornthurasook A, Gaew-Im K. Study of the infrapatellar nerve. Am J Sports Med. 1988;16:57–59. 5. Arthornthurasook A, Gaew-Im K. The sartorial nerve: its relationship to the medial aspect of the knee. Am J Sports Med. 1990;18:41–42. 6. Ebrahein NA, Mekhail AO. The infrapatellar branch of the saphenous nerve: an anatomic study. J Orthop Trauma. 1997;11:195–199. 7. Ganzoni N, Wieland K. The ramus infrapatellaris of the saphenous nerve and its importance for medial parapatellar arthrotomies of the knee. Reconstr Surg Traumat. 1978;16:95–100. 8. Kartus J, Ejerhed L, Eriksson BI, Karlsson J. The localization of the infrapatellar nerves in the anterior knee region with special emphasis on central third patellar tendon harvest: a dissection study on cadaver and amputated specimens. Arthroscopy. 1999;15:577–586. 9. Pürner J. Peripheral course of saphenous nerve. Anat Anz. 1971;129:114–132. 10. Sirang H. Saphenous nerve: origin, course, and branches. Anat Anz. 1972;130:158–169. 11. Tifford CD, Spero L, Luke T, Plancher KD. The relationship of the infrapatellar branches of the saphenous nerve to arthroscopy portals and incisions for ACL surgery: an anatomic study. Am J Sports Med. 2000;28:562–567. 12. Von Lanz T, Wachsmuth W. Praktische Anatomie. Band I, Teil 4. Bein und Statik. Berlin: Springer-Verlag; 1972:73–89. 292–300. 13. Berry MM, Starding SM, Bannister LH. Nervous system. In: Williams PL, Bannister LH, Berry MM, et al., eds. Gray’s Anatomy. The Anatomical Basis of Medicine and Surgery. 38th ed. New York: Churchill Livingstone; 1995:1280–1282 (Brit). 14. Bach BR, Jones Jr GT, Sweet FA, Hager CA. Arthroscopy-assisted anterior cruciate ligament reconstruction using patellar tendon substitution: two to four-year follow-up results. Am J Sports Med. 1994;22:758–767. 15. Shelboune KD, Trumper RV. Preventing anterior knee pain after anterior cruciate ligament reconstruction. Am J Sports Med. 1997;25:41–47. 16. Mishra AK, Fanton GS, Dillingham MF, Carver TJ. Patellar tendon graft harvesting using horizontal incisions for anterior cruciate ligament reconstruction. Arthroscopy. 1995;11:749–752. 17. Kartus J, Ejerhed L, Sernert N, Brandsson S, Karlsson J. Comparison of traditional and subcutaneous patellar tendon harvest: a prospective study of donor site-related problems after ACL reconstruction using different graft harvesting techniques. Am J Sports Med. 2000;28:328–335. 18. Tsuda E, Okamura Y, Ishibashi Y, Otsuka H, Toh S. Techniques for reducing anterior knee symptoms after ACL reconstruction using a bonepatellar tendon-bone autograft. Am J Sports Med. 2001;29:450–456.
19. Portland GH, Martin D, Keene G, Menz T. Injury to the infrapatellar branch of the saphenous nerve in anterior cruciate ligament reconstruction: comparison of horizontal versus vertical harvest site incisions. Arthroscopy. 2005;3:281–285. 20. Corry IS, Webb JM, Clingeleffer AJ, Pinczewski LA. Arthroscopic reconstruction of the anterior cruciate ligament: a comparison of patellar tendon autograft and four-strand hamstring tendon autograft. Am J Sports Med. 1999;27:444–454. 21. Bertnam C, Porsche M, Hackenbroch MH, Terhaag D. Saphenous neuralgia after arthroscopically assisted ACL reconstruction with a semitendinosus and gracilis tendon graft. Arthroscopy. 2000;16: 763–766. 22. Mochizuki T, Muneta T, Yagishita K, Shinomiya K, Sekiya I. Skin sensory change after arthroscopically-assisted anterior cruciate ligament reconstruction using medial hamstring tendons with a vertical incision. Knee Surg Sports Traumatol Arthrosc. 2004;12:198–202. 23. Figueroa D, Calvo R, Vaisman A, Campero M, Moraga C. Injury to the infrapatellar branch of the saphenous nerve in ACL reconstruction with the hamstrings technique: clinical and electrophysiological study. Knee. 2008;15:360–363. 24. Jameson S, Emmerson K. Altered sensation over the lower leg following hamstring graft anterior cruciate ligament reconstruction with transverse femoral fixation. Knee. 2007;14:314–320. 25. Kjærgaard J, Faunø L, Faunø P. Sensibility loss after ACL reconstruction with hamstring graft. Int J Sports Med. 2008;29:507–511. 26. Papastergiou SG, Voulgaropoulos H, Mikalef P. Injuries to the infrapatellar branch(es) of the saphenous nerve in anterior cruciate ligament reconstruction with four-strand hamstring tendon autograft: vertical versus horizontal incision for harvest. Knee Surg Sports Traumatol Arthrosc. 2005;14:789–793. 27. Inderhaug E, Strand T, Solheim E. The impact of sensory deficits after harvesting hamstrings autograft for ACL reconstruction. Knee Surg Sports Traumatol Arthrosc. 2015;23:1060–1064. 28. Mochizuki T, Akita K, Muneta T, Sato T. Anatomical bases for minimizing sensory disturbance after arthroscopically-assisted anterior cruciate ligament reconstruction using medial hamstring tendons. Surg Radiol Anat. 2003;25:192–199. 29. Leonhardt H, Tillmann B. Untere Extremität. In: Leonhardt H, Tillmann B, Töndury G, et al., eds. Anatomie des Menschen. Band IV. Topographie der Organsysteme, Systematik der peripheren Leitungsbahnen. Stuttgart: Georg Thieme Verlag; 1988:448–449. 30. Sanders B, Rolf R, McClelland W, Xerogeanes J. Prevalence of saphenous nerve injury after autogenous hamstring harvest: an anatomic and clinical study of sartorial branch injury. Arthroscopy. 2007;23:956–963. 31. Abram LJ, Froimson AI. Saphenous nerve injury. An unusual arthroscopic complication. Am J Sports Med. 1991;19:668–669. 32. Kopell HP, Thompson WAL. Knee pain due to saphenous-nerve entrapment. N Engl J Med. 1960;263:351–353. 33. Boon JM, Van Wyk MJ, Jordaan D. A safe area and angle for harvesting autogenous tendons for anterior cruciate ligament reconstruction. Surg Radiol Anat. 2004;26:167–171.
527.e1
SECTION XXVII Complications
132
Numbness/Saphenous Nerve Tomoyuki Mochizuki, MD, PhD, Keiichi Akita, MD, PhD, Takeshi Muneta, MD, PhD
INTRODUCTION Leg numbness due to nerve damage is one of the considerable complications after anterior cruciate ligament (ACL) reconstruction using both bone–patellar tendon–bone (BPTB) and medial hamstring tendons. Such patients especially complain of uncomfortable feelings when falling on their knees. Harvesting a BPTB graft includes risks of damaging nerves and causing sensory disturbance.1,2 Pagnani et al.3 pointed out the risk of saphenous nerve damage by harvesting medial hamstring tendons in the region of the pes anserinus. Many authors have reported the nerve distribution patterns of the infrapatellar regions.2,4–12 It is well known that both the medial cutaneous nerve of the femoral nerve and the infrapatellar branch of the saphenous nerve are distributed throughout the infrapatellar region and the anterior lower leg region.9,10,12 The saphenous nerve descends laterally along the femoral artery and enters the adductor canal. It then leaves the artery at the distal end of the canal to proceed vertically along the medial side of the knee and runs between the sartorius and gracilis tendons. In contrast, the medial femoral cutaneous nerve originates from the anterior cutaneous branches of the femoral nerve. The medial femoral cutaneous nerve runs laterally to the femoral artery, and then it crosses anteriorly to the artery at the apex of the femoral triangle to be distributed to the anteromedial thigh and the infrapatellar region. Branches of the medial femoral cutaneous nerve and the infrapatellar branch of the saphenous nerve connect to each other9,10,12 and form the subsartorial plexus in the infrapatellar region.13
BONE–TENDON–BONE AUTOGRAFT Anterior knee pain including leg numbness has been reported as a main complication of ACL reconstruction using BPTB grafts. In previous reports, the rate of postoperative anterior knee pain ranged from 4% to more than 40%.8,14,15 Mishra et al. at first described a technique using two horizontal incisions for patellar tendon harvest for the purpose of more cosmetic scarring and reducing pain and flexion limitation.16 Kartus et al.17 used a technique with two vertical incisions and reported an insensitive area compared with the insensitive area that resulted from a traditional vertical incision, which averaged 24 cm. Tsuda et al.18 changed the method of approaching the retinaculum layer, opening it horizontally rather than splitting it to protect nerves using two horizontal incisions. They reported a 17% rate of postopera tive leg numbness. Portland et al.19 compared a horizontal incision and a vertical incision and reported an infrapatellar numbness of 43% resulting from a horizontal incision and 59% resulting from a horizontal incision.
HAMSTRING AUTOGRAFT The donor site morbidity associated with harvesting a hamstring tendon graft is well recognized to be less common than that associated with harvesting a BPTB autograft.20 However, sensory disturbance is frequently observed in regions on the anterior lower leg after ACL reconstruction using medial hamstring tendons.21–27 The incidence of sensory disturbance is reported
to range from 50% to 88%.22–27 Figueroa et al. reported that a hypoesthesia area was found in 77%, with an average area of 36 cm2.23 Kjærgaard et al. reported that the incidence of sensory disturbance did not change, but the area was decreased 1-year postoperatively in 46%. Inderhaug et al. performed a long-term evaluation and reported that sensory disturbance after hamstring tendon harvesting is probably permanent.27
CLINICAL EXAMINATION We clinically examined 103 patients who had arthroscopically assisted ACL reconstructions using medial hamstring tendons to investigate the frequencies and areas of sensory disturbance.28 As an operative procedure, we made two horizontal incisions for the arthroscopy portal and one longitudinal incision (2.5–3 cm) at the pes anserinus for the tendon harvest and the tibial drill holes. We performed an inside-out technique and used Endobutton (Smith & Nephew Endoscopy, Andover, Massachusetts) for femoral fixation. The clinical examination was performed for an average of 13 months (range 6–18 months) after the operation. We detected sensory disturbance on the anterior surface of the lower leg in 60 of 103 (58%) patients. We randomly selected 13 patients with sensory disturbance, and we neurologically examined in detail the regions of sensory disturbance. The regions of sensory disturbance were of various sizes and shapes (Fig. 132.1). These regions were generally quadrilateral and located lateral to the longitudinal incision for tendon harvest and distal to the horizontal incisions for the arthroscopy portal. In the detailed neurological examination, in 8 of 13 legs (62%) the region was very close to the longitudinal incision (see Fig. 132.1A–C), and in the other five legs (38%) it was relatively far away from the longitudinal incision (see Fig. 132.1D). The region was lower than the superior end of the longitudinal incisions in 12 of 13 legs (92%); however, in one leg (8%) the region was close to the horizontal incisions (see Fig. 132.1C). The region was located in the upper half of the lower leg in 10 legs (77%); however, in three legs (23%) the region was wider than others (see Fig. 132.1B).
ANATOMICAL INVESTIGATIONS In our anatomical study, 51 lower limbs of 26 adult cadavers were used.25 In the mediodistal region of the patella, the nerve branches pierced the fascia cruris in various patterns and ran on the outer surface of the fascia to supply the skin (Fig. 132.2). On the outer surface of the fascia, the nerve branches often were connected to each other. In the regions near the horizontal and longitudinal skin incision lines, the nerve branches ran on the outer surface of the fascia cruris in all legs. After complete removal of the fasciae lata and cruris, the origin of the nerve branches was examined. The anterior surface of the lower leg was innervated by branches of the medial femoral cutaneous nerve proximally and by branches of the saphenous nerve distally. In addition, the patellar region was innervated by branches of the intermediate femoral cutaneous nerve superiorly and by branches of the medial femoral cutaneous nerve medially and inferiorly. Compared with our clinical examinations, the
CHAPTER 132 Numbness/Saphenous Nerve
525
132 P
P
H
4 (31%)
A
3 (23%)
1 (8%)
B
P
C
P
Sa
Sv H
Fig. 132.2. Examples of the distribution of the nerve branches on the fasciae lata and cruris. The nerve branches connect in various manners in the medial infrapatellar region. Some nerve branches pass through the longitudinal skin incision line. H, Skin incision for harvest; P, horizontal skin incision for portal for arthroscopy; Sa, sartorius muscle; Sv, saphenous vein.
5 (38%)
D
Fig. 132.1. Examples of cases of sensory disturbance in 13 legs. A, 4 legs (31%); B, 3 legs (23%); C, 1 leg (8%); D, 5 legs (38%). P, Skin incision for arthroscopy portal; H, skin incision for tendon harvest.
sensory disturbance regions were considered to correspond with the regions supplied by the branches of the medial femoral cutaneous and saphenous nerves. In 33 of 51 legs (65%; Fig. 132.3A and B), the infrapatellar branch of the saphenous nerve ran along the inferoposterior border of the sartorius muscle. The infrapatellar branch of the saphenous nerve pierced the distal part of the sartorius muscle in 16 of 51 legs (31%; see Fig. 132.3C). In two legs (4%; see Fig. 132.3D), the branch of the saphenous nerve emerged from the anterosuperior border of the sartorius muscle and ran lateralward horizontally. The infrapatellar region and the anterior region of the lower leg were generally supplied by branches of both the medial femoral cutaneous nerve and the saphenous nerve in various patterns. Branches of the medial femoral cutaneous nerve were also distributed to the anterior surface of the leg in eight legs (16%; see Fig. 132.3A), and branches of the saphenous nerve were also observed to supply the infrapatellar region in two legs (4%; see Fig. 132.3D). Branches of these nerves and their connections were distributed to the region around the insertion of the sartorius muscle. At least, therefore, the branches of these two nerves showed a complementary distribution and a broad transitional zone. One or more branches of the nerve ran across the line of the longitudinal incision in 88% of the cases.
DISCUSSION In numerous clinical anatomical studies, nerve distribution patterns of the infrapatellar region have been discussed.2,4–8,10,29 The nerve branches supplying the skin of the medioinferior region of the patella are recognized as the infrapatellar branches of the saphenous nerve in most studies. However, according to our study and standard anatomy textbooks,13,16 branches of the saphenous nerve and the medial femoral cutaneous nerve, which originate from the anterior cutaneous branches of the femoral nerve, are distributed to this region. In addition, the branches of the medial femoral cutaneous nerve sometimes extend to the anterior lower leg region. Interestingly, although both nerves are clearly distinguishable in origin, it is very difficult to identify the border between their distribution territories due to their numerous connections, because of their complementary distribution. On the basis of the detailed clinical and anatomical investigations, the sensory disturbance is considered to be closely related to the skin incisions. Nerve injuries due to the incisions used for the arthroscopy portal, as well as the related anatomical findings, have been reported.2,11 In the present clinical findings, the sensory disturbance region was located in close proximity to
526
SECTION XXVII Complications In
Mn
In
8 (16%)
In
B
25 (49%)
Mn
In
C
16 (31%)
Mn
Sn
Sn
Sn
Sn
A
Mn
D
2 (4%)
Fig. 132.3. Four patterns of the distribution of the nerve branches based on the findings of 51 legs. A, Branches of the medial femoral cutaneous nerve are distributed to the anterior leg region (8 legs; 16%). B, Branches of the medial femoral cutaneous nerve are distributed to the infrapatellar region, and branches of the saphenous nerve are distributed to the anterior leg region (25 legs; 49%). C, The infrapatellar branch of the saphenous nerve pierces the sartorius muscle and is distributed to the infrapatellar region (16 legs; 31%). D, The infrapatellar branch of the saphenous nerve emerges from the anterior border of the sartorius muscle and is distributed to the infrapatellar region (2 legs; 4%). In, Intermediate femoral cutaneous nerve; Mn, medial femoral cutaneous nerve; Sn, saphenous nerve.
the arthroscopy portals in only one case (see Fig. 132.1C). The branch of the medial femoral cutaneous nerve might have been injured by the incisions for the arthroscopy portal. There have been few reports on nerve injuries related to the skin incision for tendon harvest.13 The line of skin incision for tendon harvest at the pes anserinus runs across the nerve branches originating from the medial femoral cutaneous nerve and the saphenous nerve. In some patients, the region of the sensory disturbance is not adjacent to the longitudinal skin incision (see Fig. 132.1D). These cases might be explained by the various patterns of the connections and the overlapping distribution territories of the saphenous nerve and the medial femoral cutaneous nerve. The possibility of nerve injury during harvesting of the semitendinosus tendon with a tendon stripper cannot be overlooked. Sanders et al. reported that the saphenous nerve is intimately involved with the gracilis tendon and likely predisposed to damage during passage of a tendon stripper. In our study,30 the main trunk of the saphenous nerve runs distally on the medial (outer) surfaces of the tendons of the gracilis and semitendinosus muscles along the medial collateral ligament. Because the sensory disturbance region was located lateral to the longitudinal incision line in all patients, the tendon harvest using a tendon stripper cannot be the main reason for the sensory disturbance. Injury or entrapment of the main trunk of the saphenous nerve has been reported,31,32 but the sensory disturbance region due to such injury is much wider than that found in our study. If the tendon stripper caused the nerve injury, the main trunk of the saphenous nerve could be damaged along with the branches of the nerve, as previously pointed out by Pagnani et al.3 Therefore it is very important to be careful with the main trunk of the saphenous nerve, due to its close positional relationship to the tendons, to avoid sensory disturbance after ACL reconstruction. The complicated anatomical variations of the nerve branches in the infrapatellar region and the anterior lower leg region preclude absolute avoidance in any surgical knee incision (Fig. 132.4). Ebrahein and Mekhail6 described a safety zone to avoid injury of the infrapatellar branch of the saphenous nerve. However, their zone must be supplied by the branches of the medial femoral cutaneous nerve. Therefore it might be very difficult to find a completely safe zone based on the findings of the present anatomical study.25 Nevertheless an oblique incision for the tendon harvest would be
P
P
X Sa
H
Y
Z
Fig. 132.4. Schematic drawings of the nervous distribution zone in the infrapatellar region and the anterior leg region. The infrapatellar region and the anterior lower leg region are divided into three areas based on the distribution of the nervous branches: X, the region distributed by the medial femoral cutaneous nerve; Y, the transitional zone between the regions X and Z; and Z, the region distributed by the saphenous nerve. H, Skin incision for tendon harvest; P, horizontal skin incision for portal for arthroscopy.
CHAPTER 133 Hardware Complications after Anterior Cruciate Ligament Reconstruction
a good candidate to minimize the area of the sensory disturbance to avoid cutting the courses of the various branches of the nerves, based on our findings of the nerve courses and distribution. Boon et al. also suggested a safe angle for harvesting tendons is 52.5 degrees in their anatomic study.33 SELECTED READINGS
Abram LJ, Froimson AI. Saphenous nerve injury. An unusual arthroscopic complication. Am J Sports Med. 1991;19:668–669. Bertnam C, Porsche M, Hackenbroch MH, Terhaag D. Saphenous neuralgia after arthroscopically assisted ACL reconstruction with a semitendinosus and gracilis tendon graft. Arthroscopy. 2000;16:763–766. Boon JM, Van Wyk MJ, Jordaan D. A safe area and angle for harvesting autogenous tendons for anterior cruciate ligament reconstruction. Surg Radiol Anat. 2004;26:167–171. Figueroa D, Calvo R, Vaisman A, Campero M, Moraga C. Injury to the infrapatellar branch of the saphenous nerve in ACL reconstruction with the hamstrings technique: clinical and electrophysiological study. Knee. 2008;15:360–363. Inderhaug E, Strand T, Solheim E. The impact of sensory deficits after harvesting hamstrings autograft for ACL reconstruction. Knee Surg Sports Traumatol Arthrosc. 2015;23:1060–1064. Kartus J, Ejerhed L, Sernert N, Brandsson S, Karlsson J. Comparison of traditional and subcutaneous patellar tendon harvest: a prospective study of donor site-related problems after ACL reconstruction using different graft harvesting techniques. Am J Sports Med. 2000;28:328–335.
133
527
Mochizuki T, Akita K, Muneta T, Sato T. Anatomical bases for minimizing sensory disturbance after arthroscopically-assisted anterior cruciate ligament reconstruction using medial hamstring tendons. Surg Radiol Anat. 2003;25:192–199. Papastergiou SG, Voulgaropoulos H, Mikalef P. Injuries to the infrapatellar branch(es) of the saphenous nerve in anterior cruciate ligament reconstruction with four-strand hamstring tendon autograft: vertical versus horizontal incision for harvest. Knee Surg Sports Traumatol Arthrosc. 2005;14:789–793. Portland GH, Martin D, Keene G, Menz T. Injury to the infrapatellar branch of the saphenous nerve in anterior cruciate ligament reconstruction: comparison of horizontal versus vertical harvest site incisions. Arthroscopy. 2005;3:281–285. Sanders B, Rolf R, McClelland W, Xerogeanes J. Prevalence of saphenous nerve injury after autogenous hamstring harvest: an anatomic and clinical study of sartorial branch injury. Arthroscopy. 2007;23:956–963. Tifford CD, Spero L, Luke T, Plancher KD. The relationship of the infrapatellar branches of the saphenous nerve to arthroscopy portals and incisions for ACL surgery: an anatomic study. Am J Sports Med. 2000;28:562–567.
A complete reference list can be found online at ExpertConsult.com.
Hardware Complications after Anterior Cruciate Ligament Reconstruction Robert Brophy, MD, Robert G. Marx, MD
INTRODUCTION A variety of autograft and allograft tissues can be used for reconstruction of the anterior cruciate ligament (ACL), and a number of different tools and techniques can be used to achieve graft fixation, whether bone to bone or tendon to bone. Commonly used fixation devices include interference screws (metallic and bioabsorbable), suspensory fixation (the Endobutton [Acufex Microsurgical, Mansfield, Massachusetts], RetroButton [Arthrex, Naples, Florida], ACL TightRope [Arthrex, Naples, Florida]), and cross-pins. Complications related to graft fixation are often specific to the type of fixation used, although a number of themes recur. We will review each type of fixation and the related intraoperative and postoperative complications, as well as methods for managing both types of complication. Obviously the ideal management is avoidance of the complication in the first place. Skeletally immature patients are susceptible to a unique set of complications regardless of the method of fixation, and we will review these separately.
INTERFERENCE SCREWS Interference screws are a widely used method of fixation during ACL reconstruction, both for bone-to-bone fixation and soft tissue–to–bone fixation. A number of complications related to interference screws may be encountered, and they can occur intraoperatively or postoperatively.
Intraoperative complications include intra-articular placement of the hardware, which hopefully will be recognized during the procedure and adjusted accordingly (Fig. 133.1). During insertion of the screw, possible complications include laceration of the graft passing suture,1 advancement of the graft within the bone tunnel,1 graft laceration1 and even rupture,2 fracture of the graft bone plug,3 and screw breakage.4–6 To minimize the risk of lacerating the passing suture, at least one suture can be passed through the tendon at the base of the bone plug.1 To minimize the risk of graft rupture, methylene blue can be used to mark the bone-tendon junction of the graft, the anterior portion of the bone tunnel can be notched to ease the initial engagement of the screw, the cancellous edge of the bone plug can be placed facing anterior flush with the intra-articular edge of the femoral tunnel, and a protective sheath or cannula can be used to protect the graft during screw placement.2 Another helpful technique to protect the graft is to insert the femoral screw over a guidewire drilled through a cannulated screwdriver. If the graft ruptures during screw placement, a number of salvage options may be used. If a patellar tendon graft is cut at the bone-tendon junction, the graft can be reversed, placing the intact bone plug in the femoral tunnel and fixing the tendinous portion of the graft through the tibial tunnel with a post or button.2,7 If there is insufficient graft length remaining, alternative autograft or allograft should be used. To minimize the chance of graft advancement, it is important to maintain constant tension
133
REFERENCES
1. Graf B, Uhr F. Complications of intra-articular anterior cruciate reconstruction. Clin Sports Med. 1988;7:835–848. 2. Mochida H, Kikuchi S. Injury to infrapatellar branch of saphenous nerve in arthroscopic knee surgery. Clin Orthop Relat Res. 1995;320:88–94. 3. Pagnani MJ, Warner JJP, O’Brien SJ, Warren RF. Anatomic considerations in harvesting the semitendinosus and gracilis tendons and a technique of harvest. Am J Sports Med. 1993;21:565–571. 4. Arthornthurasook A, Gaew-Im K. Study of the infrapatellar nerve. Am J Sports Med. 1988;16:57–59. 5. Arthornthurasook A, Gaew-Im K. The sartorial nerve: its relationship to the medial aspect of the knee. Am J Sports Med. 1990;18:41–42. 6. Ebrahein NA, Mekhail AO. The infrapatellar branch of the saphenous nerve: an anatomic study. J Orthop Trauma. 1997;11:195–199. 7. Ganzoni N, Wieland K. The ramus infrapatellaris of the saphenous nerve and its importance for medial parapatellar arthrotomies of the knee. Reconstr Surg Traumat. 1978;16:95–100. 8. Kartus J, Ejerhed L, Eriksson BI, Karlsson J. The localization of the infrapatellar nerves in the anterior knee region with special emphasis on central third patellar tendon harvest: a dissection study on cadaver and amputated specimens. Arthroscopy. 1999;15:577–586. 9. Pürner J. Peripheral course of saphenous nerve. Anat Anz. 1971;129:114–132. 10. Sirang H. Saphenous nerve: origin, course, and branches. Anat Anz. 1972;130:158–169. 11. Tifford CD, Spero L, Luke T, Plancher KD. The relationship of the infrapatellar branches of the saphenous nerve to arthroscopy portals and incisions for ACL surgery: an anatomic study. Am J Sports Med. 2000;28:562–567. 12. Von Lanz T, Wachsmuth W. Praktische Anatomie. Band I, Teil 4. Bein und Statik. Berlin: Springer-Verlag; 1972:73–89. 292–300. 13. Berry MM, Starding SM, Bannister LH. Nervous system. In: Williams PL, Bannister LH, Berry MM, et al., eds. Gray’s Anatomy. The Anatomical Basis of Medicine and Surgery. 38th ed. New York: Churchill Livingstone; 1995:1280–1282 (Brit). 14. Bach BR, Jones Jr GT, Sweet FA, Hager CA. Arthroscopy-assisted anterior cruciate ligament reconstruction using patellar tendon substitution: two to four-year follow-up results. Am J Sports Med. 1994;22:758–767. 15. Shelboune KD, Trumper RV. Preventing anterior knee pain after anterior cruciate ligament reconstruction. Am J Sports Med. 1997;25:41–47. 16. Mishra AK, Fanton GS, Dillingham MF, Carver TJ. Patellar tendon graft harvesting using horizontal incisions for anterior cruciate ligament reconstruction. Arthroscopy. 1995;11:749–752. 17. Kartus J, Ejerhed L, Sernert N, Brandsson S, Karlsson J. Comparison of traditional and subcutaneous patellar tendon harvest: a prospective study of donor site-related problems after ACL reconstruction using different graft harvesting techniques. Am J Sports Med. 2000;28:328–335. 18. Tsuda E, Okamura Y, Ishibashi Y, Otsuka H, Toh S. Techniques for reducing anterior knee symptoms after ACL reconstruction using a bonepatellar tendon-bone autograft. Am J Sports Med. 2001;29:450–456.
19. Portland GH, Martin D, Keene G, Menz T. Injury to the infrapatellar branch of the saphenous nerve in anterior cruciate ligament reconstruction: comparison of horizontal versus vertical harvest site incisions. Arthroscopy. 2005;3:281–285. 20. Corry IS, Webb JM, Clingeleffer AJ, Pinczewski LA. Arthroscopic reconstruction of the anterior cruciate ligament: a comparison of patellar tendon autograft and four-strand hamstring tendon autograft. Am J Sports Med. 1999;27:444–454. 21. Bertnam C, Porsche M, Hackenbroch MH, Terhaag D. Saphenous neuralgia after arthroscopically assisted ACL reconstruction with a semitendinosus and gracilis tendon graft. Arthroscopy. 2000;16: 763–766. 22. Mochizuki T, Muneta T, Yagishita K, Shinomiya K, Sekiya I. Skin sensory change after arthroscopically-assisted anterior cruciate ligament reconstruction using medial hamstring tendons with a vertical incision. Knee Surg Sports Traumatol Arthrosc. 2004;12:198–202. 23. Figueroa D, Calvo R, Vaisman A, Campero M, Moraga C. Injury to the infrapatellar branch of the saphenous nerve in ACL reconstruction with the hamstrings technique: clinical and electrophysiological study. Knee. 2008;15:360–363. 24. Jameson S, Emmerson K. Altered sensation over the lower leg following hamstring graft anterior cruciate ligament reconstruction with transverse femoral fixation. Knee. 2007;14:314–320. 25. Kjærgaard J, Faunø L, Faunø P. Sensibility loss after ACL reconstruction with hamstring graft. Int J Sports Med. 2008;29:507–511. 26. Papastergiou SG, Voulgaropoulos H, Mikalef P. Injuries to the infrapatellar branch(es) of the saphenous nerve in anterior cruciate ligament reconstruction with four-strand hamstring tendon autograft: vertical versus horizontal incision for harvest. Knee Surg Sports Traumatol Arthrosc. 2005;14:789–793. 27. Inderhaug E, Strand T, Solheim E. The impact of sensory deficits after harvesting hamstrings autograft for ACL reconstruction. Knee Surg Sports Traumatol Arthrosc. 2015;23:1060–1064. 28. Mochizuki T, Akita K, Muneta T, Sato T. Anatomical bases for minimizing sensory disturbance after arthroscopically-assisted anterior cruciate ligament reconstruction using medial hamstring tendons. Surg Radiol Anat. 2003;25:192–199. 29. Leonhardt H, Tillmann B. Untere Extremität. In: Leonhardt H, Tillmann B, Töndury G, et al., eds. Anatomie des Menschen. Band IV. Topographie der Organsysteme, Systematik der peripheren Leitungsbahnen. Stuttgart: Georg Thieme Verlag; 1988:448–449. 30. Sanders B, Rolf R, McClelland W, Xerogeanes J. Prevalence of saphenous nerve injury after autogenous hamstring harvest: an anatomic and clinical study of sartorial branch injury. Arthroscopy. 2007;23:956–963. 31. Abram LJ, Froimson AI. Saphenous nerve injury. An unusual arthroscopic complication. Am J Sports Med. 1991;19:668–669. 32. Kopell HP, Thompson WAL. Knee pain due to saphenous-nerve entrapment. N Engl J Med. 1960;263:351–353. 33. Boon JM, Van Wyk MJ, Jordaan D. A safe area and angle for harvesting autogenous tendons for anterior cruciate ligament reconstruction. Surg Radiol Anat. 2004;26:167–171.
527.e1