Abstract
Background:
Posterolateral corner (PLC) injuries of the knee are being increasingly recognized and treated in current orthopaedic practice. While there are numerous systematic reviews evaluating the management and outcomes after PLC injuries, there are limited data investigating complications after PLC reconstruction or repair.
Purpose:
To systematically review the literature to determine the incidence of postoperative complications after the surgical treatment of PLC injury.
Study Design:
Systematic review; Level of evidence, 4.
Methods:
The Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (2008-2019), Embase (2008-2019), and MEDLINE (2008-2019) were queried for literature reporting on PLC reconstruction or repair, with or without concomitant ligamentous or meniscal surgery. Data including type of surgery performed, concomitant procedures, and follow-up time were extracted. Complications recorded included intra- and postoperative complications.
Results:
After the intra- and postoperative complication data of 60 studies (1747 cases) were combined, surgical management of PLC injuries was associated with an intraoperative complication rate of 0.34% (range, 0%-2.8%) and a postoperative complication rate of 20% (range, 0%-51.2%). The most common postoperative complication was arthrofibrosis (range, 0%-20%). The overall infection rate was 1.3% (range, 0%-10%). Four cases of postoperative common peroneal nerve palsy were reported. Failure of reconstruction or repair was reported in 164 (9.4%) of all cases examined (range, 0%-37.1%).
Conclusion:
Although the intraoperative rate of complications during PLC reconstructions is low, postoperative complications rates of 20% can be expected, including arthrofibrosis, infection, and neurovascular injury. PLC structures repaired or reconstructed failed in 9.4% of the cases.
Posterolateral corner (PLC) injuries of the knee have been increasingly recognized and treated over the past several decades. 13 Injuries to the PLC result in disruption of the lateral collateral ligament, popliteal tendon, and popliteal fibular ligament. They are often associated with tears of the anterior cruciate ligament (ACL) and/or posterior cruciate ligament (PCL) or combined with 3 or 4 ligament injuries of the knee during dislocation events. Isolated PCL injuries account for <30% of cases. 38 While these injuries remain a challenge to treat, an evolved understanding of the mechanics of the injury, the natural history, and the advancement of anatomically based and biomechanically validated reconstruction techniques has led to improved patient outcomes.35,37-39,54,65 Moreover, accelerated rehabilitation protocols with early range of motion have led to decreased rates of arthrofibrosis and have accelerated recovery. 52 A recent expert consensus statement attempted to outline standards of care in the management of these injuries; however, there remains significant heterogenicity in the diagnosis, surgical treatment, and rehabilitation strategies in the global surgical community.6,17 Moreover, the majority of these injuries are being treated by surgeons performing <4 cases per year, owing to the lower incidence of PLC tears in comparison with other single-ligament injuries. 17
The complexity of the PLC pathology, the association with high-energy multiligamentous knee injuries, and the infrequency of surgical treatment by individual surgeons lead to potentially high complication rates after the surgical management of PLC injury. Specific complications include common peroneal nerve injury, vascular injury, fibular head fractures, arthrofibrosis, postoperative pain syndromes, residual posterolateral instability, and general postoperative complications of the lower extremity, including infection and deep vein thrombosis. The incidence of these complications is difficult to determine from the current literature given the heterogenicity of the PLC injuries and the majority of studies being case series and low-number cohort studies. While there are numerous systematic reviews evaluating the management and outcome after PLC injuries,2,16,55,62 there is limited literature investigating the complications after PLC reconstruction or repair. The purpose of this study was to systematically review the literature to determine the incidence of postoperative complications after the surgical treatment of PLC injury. We hypothesized that a high rate of complications would occur after PLC surgery given the complexity of the anatomy, often high energy of the injury, and infrequency of treatment by surgeons.
Methods
Literature Search and Study Selection
This study was conducted in accordance with the 2009 PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) statement. The Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed (2008-2019), Embase (2008-2019), and MEDLINE (2008-2019) were queried in January 2020 for literature reporting on PLC reconstruction or repair, with or without concomitant ligamentous or meniscal surgery. Database queries were performed using the following Boolean search terms: (“posterolateral corner” OR “fibular collateral ligament” OR “lateral collateral ligament” OR “popliteus tendon” OR “popliteofibular ligament”) AND (repair OR reconstruction OR outcomes OR complications).
Each identified study was reviewed and included in the present analysis if it reported on complications of PLC reconstruction or repair. Specific inclusion criteria were level 1-4 studies that explicitly discussed the presence or absence of intra- or postoperative complications after PLC reconstruction or repair. Treatment of grade III PLC tears included repair, partial reconstructions with fibular-based techniques, anatomic reconstructions with fibular and tibial tunnels, as well as treatment in the context of multiligament knee injuries. Articles were excluded if they did not explicitly report on the presence or absence of complications after surgery, reported on open knee dislocations, or included only pediatric patients (age <18 years). Two investigators (B.M. and N.S.J.) independently screened articles first by title, followed by abstracts and finally full text, when appropriate. Full-text articles were reviewed if further assessment of inclusion and exclusion criteria was required. All references from included studies were screened to identify additional articles absent from the primary query. This study was registered with PROSPERO and pending because of the COVID-19 pandemic.
Data Extraction
A customized spreadsheet and a modified information extraction table were created to record all relevant data from the included studies, such as publication information, design, level of evidence, population, type of surgery, concomitant procedures, complications, and follow-up time. Complications were either intraoperative (fractures, damage from reamer, and neurovascular injuries) or postoperative: hematoma, arthrofibrosis, pain syndromes, deep vein thrombosis or pulmonary embolism, nerve or vascular injuries, infection, wound dehiscence or fistula formation, fractures (intra- or postoperative), symptomatic hardware removal, and recurrent posterolateral instability (side-to-side difference >4-mm varus instability or >4-mm external rotation at 30° in flexion) or need for reoperation. While concomitant procedures and multiligament reconstructions were included in this study, complications directly related to other parts of the procedure were not recorded.
Statistical Statement
The outcome measures were rates of overall and specific types of complications. Complication rates were computed as the cumulative number of complications divided by the total number of all study participants. The average number of each complication reported per study was also evaluated and included as applicable.
Results
Demographic Data
In total, 60 studies were eligible for inclusion in this study after a database query (Figure 1). Study design, level of evidence, total number of patients, follow-up, and age and sex of the patients were extracted and are presented in Table 1. Of 60 studies, 7 reported no complications.1,56,63,79,81-83 The review included 1420 partial or anatomic PLC reconstructions and 327 PLC repairs. The mean ± SD age of all patients from the included studies was 30 ± 4.4 years, and the average follow-up was 36.7 months (range, 2.9-232.8 months). No randomized controlled trials (level 1) were included. Five prospective cohort studies (level 2), 10 retrospective cohort studies (level 3), 2 case-control studies (level 3), and 43 case series/reports (level 4) were included.
PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) diagram outlining steps included in the systematic review of queried articles. PLC, posterolateral corner.
Demographic Variables of All Included Studies a
Dashes indicate data not reported. AJSM, American Journal of Sports Medicine; F, female; IJCEM, International Journal of Clinical and Experimental Medicine; IJSCR, International Journal of Surgery Case Reports; JBJS, Journal of Bone and Joint Surgery; JOT, Journal of Orthopaedics and Traumatology; KSSTA, Knee Surgery, Sports Traumatology, Arthroscopy; M, male; OTSR, Orthopaedics & Traumatology, Surgery & Research.
Surgical Technique and Concomitant Procedures
The range of surgery performed in the included studies is shown in Table 2. Six studies described partial PLC reconstruction or repair, including fibular collateral ligament (FCL) reconstruction, popliteus tendon reconstruction, and popliteofibular ligament reconstruction. Thirteen studies reported reconstruction of ≥2 ligaments with concurrent PLC reconstruction. Two studies reported PLC reconstruction alongside another procedure, such as high tibial osteotomy or Gerdy tubercle avulsion fracture reduction and fixation. Other concomitant procedures included meniscal repair4,5,61,80,82 and partial meniscectomy.5,32-34,61,76,80,82
Surgery Performed in All Included Studies
Intraoperative Complications
Six intraoperative complications were identified, representing an overall intraoperative complication rate of 0.34% (range, 0%-2.8%) (Table 3). The most common intraoperative complication was fibular fracture, including incomplete fracture of the fibular neck during fibular tunnel construction 43 and complete fracture of the fibular head during fibular tunnel reconstruction.34,73 Two studies reported direct damage to the common peroneal nerve by a reamer or guide pin.28,43 The studies did not explicitly specify the damage done by the reamer; however, both cases of reamer damage occurred during femoral tunnel drilling during the PLC reconstruction procedure.
Incidence of Intra- and Postoperative Complications a
DVT, deep vein thrombosis; LOA, lysis of adhesions; MUA, manipulation under anesthesia; OR, operating room; PE, pulmonary embolism; PLC, posterolateral corner; ROM, range of motion.
Postoperative Complications
A total of 343 postoperative complications were noted among all studies (Figure 2), representing an overall postoperative complication rate of approximately 20% of the 1747 cases. Range of motion deficit and arthrofibrosis composed 72 cases (4.1%; range, 0%-20.0%). Of the patients who developed arthrofibrosis, 28 required a return to the operating room for manipulation under anesthesia (MUA), with 10 requiring an arthroscopic lysis of adhesions (LOA). Pain was categorized as having a pain syndrome for a prolonged period and to a higher extent than normal postoperative pain. Two studies reported cases of complex regional pain syndrome postoperatively.64,73
Intra- and postoperative complications after posterolateral corner reconstruction. DVT, deep vein thrombosis; LOA, lysis of adhesions; MUA, manipulation under anesthesia; PE, pulmonary embolism; PLC, posterolateral corner; ROM, range of motion.
Postoperative infections were reported in 23 cases (1.3%; range, 0%-10%). There were 4 cases of lateral superficial infection.22,30 One case of postoperative infection required removal of the PLC grafts and revision PLC surgery. 37 Two patients developed septic arthritis requiring intravenous antibiotics and debridement. One case of septic arthritis was noted, which resolved with prolonged antibiotic therapy and immobilization. 4 One patient had a delayed wound infection of the posterolateral approach requiring wound debridement. 22 Another patient developed a deep infection, which was treated with serial irrigation and debridement with graft retention. 26 Other cases included superficial suture abscess, 9 infection along the tibial drill tunnel, 27 infection related to FCL reconstruction requiring graft removal, 57 and infection requiring irrigation and debridement. 69 The remaining 2 cases were infections that were related directly to concomitant procedures performed (specifics included 1 ACL anterior wound infection 5 and 1 stitch abscess from a concurrent medial meniscal repair requiring surgical debridement). 5 There were 2 cases of infection that healed after arthroscopic irrigation and debridement without graft removal. 44
There were 4 cases of peroneal nerve injury. The 3 reported nerve deficits occurred postoperatively after multiligament knee reconstructions.33,43,68 The first patient underwent PLC reconstruction based on the modified 2-tailed technique. 68 It was not specified what deficits the patient experienced or whether a common peroneal nerve neurolysis was performed. The second patient developed a transient peroneal nerve palsy that resolved spontaneously 3 months after surgery without residual deficits. 33 This patient underwent PCL reconstruction with use of an Achilles tendon–bone allograft and PLC reconstruction with modified biceps rerouting tenodesis for PLC insufficiency. The third patient had sustained direct damage to the peroneal nerve by the reamer or guide pin. 43 The patient had complete recovery at final follow-up. The fourth patient developed transient common peroneal neurapraxia, which resolved by 4 weeks postoperatively. 37 This patient underwent anatomic PLC reconstruction with Achilles tendon–bone allografts. With the 4 cases mentioned, there were 2 additional cases of intraoperative damage to the peroneal nerve. These 2 patients had complete recovery at final follow-up. The postoperative deficits that the 2 patients experienced were not specified.28,43
Five patients experienced wound dehiscence, with 2 subsequently developing fistulas secondary to loss of capsular tissue.68,69 Five patients (0.29%; range, 0%-5.0%) developed hematomas postoperatively. One miscellaneous complication was reported as a recurrent effusion. 60 There were no intraoperative vascular complications. One patient developed a deep vein thrombosis postoperatively, followed by a pulmonary embolism requiring protracted hospital recovery and low molecular weight heparin. 4
A total of 55 patients (3.1%) required removal of surgical hardware directly related to the PLC procedure (range, 0%-43.9%). Miscellaneous cases requiring reoperation included the following: postoperative symptomatic failure, 13 ruptured biceps femoris tendon secondary to pressure necrosis by screw washer in 2 patients undergoing revision surgery, 33 biceps femoris transfer, 57 high tibial osteotomy (performed for unrecognized malalignment before PLC reconstruction), 61 proximal advancement of the posterolateral complex, 57 heterotopic ossification, and medial femoral condyle osteonecrosis. 68
Failure of Operative Procedure
A total of 164 (9.4%) failed PLC cases were reported (range, 0%-37.1%). Failure of surgery was defined as residual side-to-side difference of varus laxity >4 mm, external rotation in flexion >4°, or return to the operating room for revision of PLC reconstruction. There were 65 cases of documented residual or recurrent varus or posterolateral instability. ** One case that underwent anatomic PLC reconstruction required PLC graft removal and revision reconstruction after a postoperative infection. 37 There were 63 cases of failure of an anatomic-type PLC reconstruction that required revision reconstruction. †† An additional 5 cases utilized the fibular sling–based technique.10,41,57 One study noted 2 cases of surgical failure after using the modified biceps rerouting technique. 32 Thirteen failed operations occurred after utilizing the modified 2-tailed technique. 68 Two studies had a total of 15 failed PLC repairs.50,68 In 1 of the failed PLC repair cases, the FCL avulsed off the fibula and popliteus off the femur, and the suture anchor pulled out from the fibula. One study reported graft failure of PLC and ACL grafts, requiring return to the operating room 1 time. 10 Eleven additional patients underwent isolated revision of other ligaments repaired during PLC surgery. These 11 cases were not included in the overall complication rate. One study cited 1 failure of the ACL graft in an ACL + PLC reconstruction. 70 Five cases reported graft failure and revision of the PCL or ACL. 22 These graft failures occurred in patients in which the chosen technique for PLC reconstruction was that recommended by Stannard et al. 69 The remaining 5 graft failures and revisions did not specify the type of graft that failed and specific revision surgery performed. 60
Discussion
The main finding of this study was that the surgical management of PLC injuries was associated with a low intraoperative complication rate of 0.34% (range, 0%-2.8%) but a relatively high postoperative complication rate of 20.0% (range, 0%-51.2%). Approximately 60% of the PLC procedures included in this review were nonisolated PLC reconstructions or repairs. This is corroborated by current literature stating that isolated PLC injuries account for <30% of all PLC injuries.14,15,38 As such, the complication rate in this review can be compared with that seen in multiligament knee literature, which ranges from 6.3% 48 to 28% 7 in larger cohort studies. The variability in complications in PLC and multiligament injuries highlights the heterogenicity of these injuries, which can occur in low-energy twisting events or high-energy trauma, such as motor vehicle collisions, with variable proportions of cases represented in different series.
Arthrofibrosis was a common complication, having a rate of 4.1% of all cases examined, with 1.6% of patients returning to the operating room for MUA or LOA. However, this value is lower than expected given the current rates of MUA in the knee ligament literature. Hanley et al 19 retrospectively reviewed 121 multiligament knee reconstructions and found that 14% required a return to the operating room for stiffness. The higher number of ligaments involved increased the risk of postoperative stiffness. LaPrade et al 36 reported on the outcomes of 194 multiligament knee reconstructions performed in a single stage. Using a postoperative protocol allowing for immediate 0°-90° range of motion, regardless of the number of ligaments involved, they found that 9.3% of patients were diagnosed with arthrofibrosis requiring MUA or LOA at an average 4.9 months from the index procedure. Noyes et al 59 reviewed the incidence of arthrofibrosis after 443 ACL reconstructions with or without collateral ligament repair/reconstruction. They determined that 2.7% of patients required MUA or LOA between postoperative weeks 6 and 14. Their protocol aggressively treats stiffness with an early return to the operating room for MUA, even in cases with PLC reconstruction. We would suggest a more cautious approach with PLC injuries because early MUA can result in loss of graft integrity. An interval of 4 months from the time of index surgery to MUA or LOA allows for graft healing and avoids residual instability after MUA. Early range of motion postoperative rehabilitation protocols have significantly decreased the incidence of arthrofibrosis and improved patient outcomes. 53
Four cases of postoperative common peroneal nerve palsy and 2 cases of intraoperative common peroneal nerve damage were reported. This was lower than expected given the anatomic proximity to the biceps femoris and fibular head. All cases resolved by final follow-up, and no cases included permanent dysfunction or a need for secondary neurolysis or tendon transfer surgery. It is possible that transient foot drop in the first 24 to 48 hours after surgery is more common than reported in this review because this may not often be documented as a complication. Ridley et al 60 examined the incidence of peroneal nerve injuries in a cohort of 61 PLC injuries. At the time of initial evaluation, 13 patients had complete nerve injuries, and 3 had partial nerve injuries (26.2%). Of the complete injuries, 3 were complete transections and 10 were stretch injuries, of which 50% had complete recovery. While the clinical outcomes of patients with complete peroneal nerve injury remain guarded in the setting of PLC injury, this review suggests that in the setting of no preexisting pathology, the incidence of postoperative dysfunction is rare.
The overall infection rate was 1.3% (6.6% of all complications), with 3 cases of septic arthritis. The low rate of septic arthritis is likely due to the fact that 50% of cases reviewed did not have an intra-articular concomitant graft placed. Moreover, only a portion of the PLC reconstructions were performed using a technique in which an arthrotomy is performed for popliteal tendon tunnel placement. In comparison, the overall infection rates after ACL reconstruction have consistently been between 0.14% and 2.6%.18,49 Specifically, septic arthritis is a rare event, with an incidence of 0.14% in a series of 3500 consecutive ACL reconstructions. 25 Sivasundaram et al 67 performed a retrospective cohort study investigating complications after multiligament knee reconstruction in 481 patients. By 30 days postoperatively, superficial surgical site infections occurred in 1.25%, deep wound infection in 0.62%, and wound dehiscence in 0.42%. The results of our review are in line with the rates of infections after knee ligament surgery, for intra-articular and wound complications.
The surgical technique for addressing PLC injuries varied across studies, as numerous techniques to repair, augment, or reconstruct the PLC have been described. This includes the Clancy method describing biceps tenodesis, the combined tibia- and fibula-based anatomic PLC reconstruction using tibial and fibular slings described by LaPrade and Wentorf, 39 and the fibula-based reconstruction described by Fanelli and Larson. 11 Despite this variation in technique, the intraoperative complication rate was low. Fibular fracture occurred in 3 patients. Damage to the common peroneal nerve by the reamer during femoral tunnel placement occurred in 2 patients. Moatshe et al 52 described the optimal angle of femoral tunnel placement of PLC reconstructions using 3-dimensional knee models. Aiming the femoral tunnels of the FCL and popliteus 35° anterior and slightly proximal avoids tunnel convergence with ACL tunnels as well as intra-articular penetration of the trochlea.
Overall, 9.4% of included PLC cases were documented to have residual instability or a return to the operating room for graft revision (range, 0%-37.1%). Geeslin et al16,55 performed a 2-part systematic review to determine clinical outcomes of the treatment of acute and chronic grade III PLC injuries. On the basis of documented varus instability (International Knee Documentation Committee C/D, American Medical Association grade II/III, or >4-mm gapping varus stress radiographs), they determined an overall failure rate of 9% of acutely reconstructed cases as compared with 38% of repaired cases. Chronic cases, defined as at least 1 month from injury, had a 10% failure rate. While our study included acute repairs, acute reconstructions, and chronic injuries, the fact that the overall failure rate was lower in this series is likely due to several differences that exist in the inclusion criteria of our study in comparison with that of Geeslin et al. 16 To identify all forms of intra- and postoperative complications, we included case reports and small case series with short-term follow-up. We also included studies that did not specifically include clinical outcomes but documented short-term complications. The studies by Geeslin et al16,55 included only investigations with >2-year follow-up, specifically reporting on objective outcome data.
This study should be interpreted in the context of the following limitations. After review of the current literature, no level 1 studies met the inclusion criteria at the time of the literature search. Of 60 included studies, 43 were case reports or case series. This indicates the need for higher-quality studies on the problems, complications, reoperations, and revisions after PLC reconstruction or repair. A meta-analysis could not be performed because of the lack of homogeneity; thus, a systematic review was performed. However, systematic reviews are quantitatively limited by the quality of the included studies. Future level 1 studies are necessary to investigate treatment and management of PLC injuries and help develop a strong consensus regarding optimal management techniques.
Additionally, many studies noted minor concomitant procedures associated with larger partial or complete PLC reconstruction or repair, such as meniscectomy or meniscal repair. These associated procedures alongside the variation in type of PLC reconstruction or repair performed introduce another difficulty in drawing broad conclusions from this study and emphasize the lack of homogeneity in studies owing to multiple confounding variables. While this limitation highlights the necessity of more standardized level 1 studies, it is highly unlikely that a patient cohort of isolated PLC reconstructions or repairs with complete elimination of all confounding variables can be created, as this represents the clinical reality of these injuries.
Conclusion
Although the intraoperative rate of complications during PLC reconstructions is low, postoperative complications rates of 20% can be expected, including arthrofibrosis, infection, and neurovascular injury. PLC repairs or reconstructions failed in 9.4% of the cases.
Footnotes
Submitted May 6, 2020; accepted September 1, 2020.
One or more of the authors has declared the following potential conflict of interest or source of funding: R.F.L. has received royalties from Arthrex and Smith & Nephew and consulting fees from Smith & Nephew. J.C. has received consulting fees from Smith & Nephew, Arthrex, Linvatec Corp, and DePuy Synthes Products and hospitality payments from Medical Device Business Services Inc, Stryker Corp, and Medwest Associates. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
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References
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