Search

Background: Stiffness is a common reason for suboptimal clinical outcomes after primary total knee arthroplasty (pTKA). There is a lack of consensus regarding its definition, which is often conflated with its histopathologic subcategory-i.e., arthrofibrosis. There is value in refining the definition of acquired idiopathic stiffness in an effort to select for patients with arthrofibrosis. We conducted a systematic review and meta-analysis to establish a consensus definition of acquired idiopathic stiffness, determine its prevalence after pTKA, and identify potential risk factors for its development., Methods: MEDLINE, Embase, Cochrane Controlled Register of Trials (CENTRAL), and Scopus databases were searched from 2002 to 2017. Studies that included patients with stiffness after pTKA were screened with strict inclusion and exclusion criteria to isolate the subset of patients with acquired idiopathic stiffness unrelated to known extrinsic or surgical causes. Three authors independently assessed study eligibility and risk of bias and collected data. Outcomes of interest were then analyzed according to age, sex, and body mass index (BMI)., Results: In the 35 included studies (48,873 pTKAs), the mean patient age was 66 years. In 63% of the studies, stiffness was defined as a range of motion of <90° or a flexion contracture of >5° at 6 to 12 weeks postoperatively. The prevalence of acquired idiopathic stiffness after pTKA was 4%, and this did not differ according to age (4%, I = 95%, among patients <65 years old and 5%, I = 96%, among those ≥65 years old; p = 0.238). The prevalence of acquired idiopathic stiffness was significantly lower in males (1%, I = 85%) than females (3%, I = 95%) (p < 0.0001) as well as in patients with a BMI of <30 kg/m (2%, I = 94%) compared with those with a BMI of ≥30 kg/m (5%, I = 97%) (p = 0.027)., Conclusions: Contemporary literature supports the following definition for acquired idiopathic stiffness: a range of motion of <90° persisting for >12 weeks after pTKA in patients in the absence of complicating factors including preexisting stiffness. The mean prevalence of acquired idiopathic stiffness after pTKA was 4%; females and obese patients were at increased risk., Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background: Periprosthetic joint infection (PJI) of the knee with concurrent disruption of the extensor mechanism is a devastating complication. Historically, knees with such complications have been salvaged with use of an arthrodesis or amputation. The purpose of this study was to assess the survival and functional outcomes of a 2-stage exchange arthroplasty combined with knitted monofilament polypropylene (Marlex; C.R. Bard) mesh reconstruction of the extensor mechanism., Methods: From 2000 to 2015, 16 patients underwent a 2-stage exchange arthroplasty and Marlex-mesh reconstruction for PJI with an extensor mechanism disruption. The study included 9 male patients and 7 female patients with a mean age at the time of reimplantation and mesh reconstruction of 64 years. The mean follow-up was 4 years. PJI was diagnosed on the basis of the Musculoskeletal Infection Society criteria. Clinical outcomes, including survivorship, Knee Society Score (KSS) results, and complications, were assessed., Results: Of 16 reconstructions, 13 were in place at the time of the latest follow-up. At 2 years, survivorship free of mesh failure was 86%, survivorship free of PJI was 87%, and survivorship free of PJI or mesh failure was 75%. The mean KSS improved from 48 prior to resection to 74 after mesh reconstruction and reimplantation. The mean extensor lag improved from 31° prior to resection to 3° after mesh reconstruction. Two patients required mesh revision, 1 patient required an above-the-knee amputation for complex wound complications related to reinfection, 1 patient developed a reinfection requiring irrigation and debridement, and 1 patient developed a superficial infection that required debridement., Conclusions: Two-stage exchange arthroplasty combined with Marlex-mesh reconstruction of the extensor mechanism is a viable alternative to knee arthrodesis or amputation. At 2 years, 75% of mesh reconstructions were in place and without evidence of PJI. Moreover, the functional outcomes were improved, with a negligible extensor lag., Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Background: Disruption of the extensor mechanism after total knee arthroplasty (TKA) is debilitating, and the reported results of numerous reconstructive options have varied. We previously reported the early results of 13 patients who underwent reconstruction of the extensor mechanism with use of Marlex mesh. The purpose of the current study was to assess results in a larger cohort of patients, with an emphasis on the survivorship of the mesh, clinical results, and complications., Methods: During the period of 2000 to 2015 at a single tertiary care academic institution, 77 patients (77 TKAs) underwent reconstruction with use of Marlex mesh for an extensor mechanism disruption (27 quadriceps tendon disruptions, 40 patellar tendon disruptions, and 10 patellar fractures). The mean patient age at the time of reconstruction was 65 years; 70% of the patients were female. The mean body mass index was 35 kg/m. The mean follow-up was 4 years. Eighteen (23%) of the patients underwent mesh reconstruction with the primary TKA in place, and 59 (77%) had mesh reconstruction at the time of revision TKA. The mean time between disruption and reconstruction was 7 months. Twenty (26%) of the patients had previously undergone attempted extensor mechanism reconstruction at outside institutions., Results: Sixty-five of the 77 mesh reconstructions were in place at the time of the latest follow-up. Twelve patients experienced a failure that required mesh revision: 5 for patellar tendon rupture, 5 for quadriceps tendon rupture, and 2 for symptomatic lengthening. Four additional patients with mesh failure were treated nonoperatively with bracing. The 2-year survivorship free of mesh revision was 86% for patients with no prior reconstruction and 95% for patients with previous reconstructions of the extensor mechanism that did not involve Marlex mesh. Knee Society Score (KSS) results significantly improved following reconstruction (p < 0.001). Extensor lag improved by a mean of 26°, with mean postoperative extensor lag measuring 9° (p < 0.001)., Conclusions: Reconstruction of the extensor mechanism with use of Marlex mesh is a viable option in patients with catastrophic disruption after TKA. At the time of the latest follow-up, 84% of the mesh reconstructions were in place and the functional outcomes were excellent, with mean improvement in extensor lag of 26°. Extended follow-up is required, but the results of this large series with a mean follow-up of 4 years are encouraging., Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.