Does knee malalignment predict the efficacy of realignment therapy for patients with knee osteoarthritis?

BACKGROUND: Realignment therapies, including knee braces, foot orthoses and shoes are prescribed to patients with medial knee osteoarthritis (OA) with the goal of unloading the medial tibiofemoral (TF) compartment. It is uncertain whether realignment therapies have different effects in those with knee malalignment. We studied whether the efficacy of realignment therapy for pain and function in persons with medial TF OA is predicted by the severity of the baseline knee malalignment. METHODS: The baseline characteristics of 48 participants with moderate to severe medial knee OA were collected. Participants' pain and function were measured using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale before and after 12 weeks of realignment therapy using a valgus unloader knee brace plus bilateral neutral foot orthoses and motion control shoes. Anatomical axis (AA) was measured on weight-bearing knee radiographs by a blinded reader and knee malalignment was categorized as either varus malaligned (moderate or severe) or neutral according to the AA angle. We assessed for differences in response to treatment according to alignment category. General linear statistical models were generated to determine which of the measured alignment variables and covariates predicted change in the pain outcome. RESULTS: Anatomical axis knee alignment was not a significant predictor of pain or function change with active treatment. Baseline WOMAC scores were the best predictor of change in WOMAC (P < 0.01 and P = 0.06 for pain and function, respectively). CONCLUSIONS: Baseline knee alignment did not predict the efficacy of 12 weeks realignment therapy in participants with medial tibiofemoral OA. [Correction added on 27 August 2015, after first online publication: 'did predict' has been corrected to 'did not predict' in the conclusions of the abstract section.].

Bilateral distal biceps tendon ruptures.

PURPOSE: To determine the incidence of bilateral distal biceps tendon ruptures. METHODS: A retrospective review of 321 patients who underwent operative repair of a distal biceps tendon rupture between 1988 and 2010 identified 26 patients with bilateral ruptures. We recorded patient age, mechanism of injury, time between symptom onset before the first surgery and subsequent contralateral symptoms, and time between surgeries. RESULTS: Twenty-two bilateral ruptures were confirmed intra-operatively, 3 by MRI, and 1 was lost to follow up. A total of 23 bilateral ruptures (92%) occurred in men. The average age at the initial rupture was 44 years (range, 29-74 y). The average age at subsequent rupture was 48 years (range, 36-79 y). Excluding the 2 women (age 72 and 79 y), the average age at the initial rupture was 42 years and the average age at subsequent rupture was 46 years. The average interval between ruptures was 4.1 years (range, 0.8-13.9 y). The initial rupture occurred in the dominant extremity in 12 cases (50%) and in the nondominant extremity in 10 cases (42%); in 3 patients (8%) the dominance was not documented or ambidextrous. Thirty-three percent were heavy laborers, 3 patients had a smoking history, and 1 patient reported a history of steroid use. Twenty-two patients (88%) had the second side repaired, where we noted that 12 (55%) of the second tendon ruptures were partial tears. CONCLUSIONS: The 8% cumulative incidence of bilateral biceps tendon ruptures in a consecutive series of biceps tendon repairs may be higher because not all patients were contacted, which introduced a sampling bias. This 8% rate is markedly higher than the reported rate of 1.2 per 100,000 for an isolated distal biceps tendon rupture. This implies that patients with a distal biceps tendon rupture are at risk for a rupture on the contralateral side. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic III.