Arthroscopic popliteal tenotomy grants satisfactory outcomes in total knee arthroplasty with persistent localised posterolateral pain and popliteus tendon impingement.

PURPOSE: The purpose was to estimate the prevalence of popliteus tendon impingement following TKA, and to describe the characteristics and the differential diagnosis protocol for this rare condition. The hypothesis was that arthroscopic popliteal tenotomy in TKA patients with suspected popliteus tendon impingement would relieve pain and improve satisfaction.

METHODS: Of 741 TKAs performed over three years, eight (1.1%, all women) had suspected popliteus tendon impingement, of which seven had severe localised posterolateral knee pain and one global knee pain. Upon confirmation of popliteus tendon impingement, arthroscopic popliteal tenotomy was performed, and outcomes (Pain on visual analogue scale (pVAS; best, 0; worst, 10), Oxford Knee Score (OKS; best, 48; worst, 0) and satisfaction (best, 100%; worst, 0%) assessed at mean 18-month follow-up.

RESULTS: At four to 30 months after TKA, arthroscopic exploration revealed popliteus tendon impingement in all eight knees. Six reported complete pain relief (pVAS, 0) the day following arthroscopic popliteal tenotomy, whilst one reported some residual pain (pVAS, 2). The remaining patient with global pain reported no pain relief, and required revision TKA at 12 months. Excluding the revised TKA, OKS was between 19 and 43, and satisfaction was rated ≥ 80% in five of the remaining seven patients.

CONCLUSIONS: Arthroscopic popliteal tenotomy relieved symptoms in TKA patients with persistent localised posterolateral pain and a positive popliteus test. These findings suggest that the popliteus test is reliable to diagnose popliteus tendon impingement following TKA, which could be treated by arthroscopic popliteal tenotomy.

LEVEL OF EVIDENCE: Level IV, Small case series.