In vivo intervertebral disc mechanical deformation following a treadmill walking "stress test" is inversely related to T1rho relaxation time.

OBJECTIVE: To assess the in vivo relationship between the mechanical response of intervertebral discs (IVDs) to dynamic activity and IVD biochemical composition assessed via T1rho relaxation imaging. DESIGN: Eighteen asymptomatic participants with no history of low back pain (LBP), injury, or surgery underwent magnetic resonance (MR) imaging of their lumbar spine prior to and immediately following a treadmill walking "stress test." Anatomic (SPACE, FLASH) MR images were obtained pre- and post-exercise and utilized to measure IVD mechanical deformation. Quantitative (T1rho) imaging was performed pre-exercise to reflect IVD composition. Pre-exercise anatomic images were also utilized to assess IVD degenerative status based on the modified Pfirrmann scale. To quantify mechanical response, 3D surface models of the L1-L2-L5-S1 IVDs were created from manual segmentations of pre- and post-exercise anatomic images and utilized to assess changes in IVD height. IVD strain (%) was defined as change in IVD height normalized to pre-activity height. Linear mixed models were used to assess the relationships between IVD mechanical deformation (strain), composition (T1rho relaxation time), and degenerative status (Pfirrmann grade). RESULTS: Increased compressive IVD strain was associated with lower T1rho relaxation times in the nucleus pulposus (NP) of the disc (ßT1rho=5.07,CI:[1.52,7.77],Rmarg2=0.52,p=0.005). Thus, an inverse relationship between IVD strain and NP T1rho relaxation time was observed. CONCLUSION: The in vivo mechanical response of the IVD to the "stress test" was sensitive to differences in NP composition. The results of this study suggest that quantification of in vivo IVD mechanical function and composition may provide insight into IVD health.

Neuromuscular electrical stimulation is effective in strengthening the quadriceps muscle after anterior cruciate ligament surgery.

PURPOSE: Reduced ability to contract the quadriceps muscles is often found immediately following anterior cruciate ligament (ACL) surgery. This can lead to muscle atrophy and decreased function. Application of neuromuscular electrical stimulation (NMES) may be a useful adjunct intervention to ameliorate these deficits following ACL surgery. The purpose of this review was to determine whether NMES in addition to standard physical therapy is superior to standard physical therapy alone in improving quadriceps strength or physical function following ACL surgery. METHODS: A computer-assisted literature search was conducted utilizing PubMed, CINAHL, PEDro and Cochrane Library databases for randomized clinical trials where patients after ACL surgery received NMES with the outcome of muscle strength and/or physical function. Random effect models were used to pool summary estimates using standardized mean differences (SMD) for strength outcomes. Physical function outcomes were assessed qualitatively. Methodological quality was assessed from the Physiotherapy Evidence Database (PEDro)-score. RESULTS: Eleven studies met our inclusion criteria; results from six of these were pooled in the meta-analysis showing a statistically significant short-term effect of NMES (4-12 weeks) after surgery compared to standard physical therapy [SMD = 0.73 (95% CI 0.29, 1.16)]. Physical function also improved significantly more in the NMES groups. PEDro scores ranged from 3/10 to 7/10 points. CONCLUSION: NMES in addition to standard physical therapy appears to significantly improve quadriceps strength and physical function in the early post-operative period compared to standard physical therapy alone. LEVEL OF EVIDENCE: I.

Diagnostic accuracy of clinical tests for the diagnosis of hip femoroacetabular impingement/labral tear: a systematic review with meta-analysis.

BACKGROUND: Surgery for hip femoroacetabular impingement/acetabular labral tear (FAI/ALT) is exponentially increasing despite lacking investigation of the accuracy of various diagnostic measures. Useful clinical utility of these measures is necessary to support diagnostic imaging and subsequent surgical decision-making. OBJECTIVE: Summarise/evaluate the current diagnostic accuracy of various clinical tests germane to hip FAI/ALT pathology. METHODS: A computer-assisted literature search of MEDLINE, CINAHL and EMBASE databases using keywords related to diagnostic accuracy of the hip joint, as well as the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for the search and reporting phases of the study. Quality assessment of bias and applicability was conducted using the Quality of Diagnostic Accuracy Studies-2 (QUADAS-2). Random effects models were used to summarise sensitivities (SN), specificities (SP), diagnostic odds ratio (DOR) and respective confidence intervals (CI). RESULTS: The employed search strategy revealed 21 potential articles, with one demonstrating high quality. Nine articles qualified for meta-analysis. The meta-analysis demonstrated that flexion-adduction-internal rotation (pooled SN ranging from 0.94 (95% CI 0.90 to 0.97) to 0.99 (95% CI 0.98 to 1.00); DOR 5.71 (95% CI 0.84 to 38.86) to 7.82 (95% CI 1.06 to 57.84)) and flexion-internal rotation (pooled SN 0.96 (95% CI 0.81 to 0.99); DOR 8.36 (95% CI 0.41 to 171.3) tests possess only screening accuracy. CONCLUSIONS: Few hip physical examination tests for diagnosing FAI/ALT have been investigated in enough studies of substantial quality to direct clinical decision-making. Further high-quality studies across a wider spectrum of hip pathology patients are recommended to discern the confirmed clinical utility of these tests. TRIALS REGISTRATION NUMBER: PROSPERO Registration # CRD42014010144.