Establishing the Minimal Clinically Important Difference and Substantial Clinical Benefit for the Pain Visual Analog Scale in a Postoperative Hand Surgery Population.

PURPOSE: Although the pain visual analog scale (VAS-pain) is a ubiquitous patient-reported outcome instrument, it remains unclear how to interpret changes or differences in scores. Therefore, our purpose was to calculate the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) for the VAS-pain instrument in a nonshoulder hand and upper extremity postoperative population. METHODS: Adult postoperative patients treated by 1 of 5 fellowship-trained orthopedic hand surgeons at a single tertiary academic medical center were identified. Inclusion required VAS-pain scores at baseline (up to 3 months before surgery) and follow-up (up to 4 months after surgery), in addition to a response to a pain-specific anchor question at follow-up. The MCID estimates were calculated with (1) the 1/2 standard deviation method; and (2) an anchor-based approach. The SCB estimates were calculated with (1) an anchor-based approach; and (2) a receiver operator curve method that maximized the sensitivity and specificity for detecting a "much improved" pain status. RESULTS: There were 667 and 148 total patients included in the MCID and SCB analyses, respectively. The 1/2 standard deviation MCID estimate was 1.6, and the anchor-based estimate was 1.9. The anchor-based SCB estimate was 2.2. The receiver operator curve analysis yielded an SCB estimate of 2.6, with an area under the curve of 0.72, consistent with acceptable discrimination. CONCLUSIONS: We propose MCID values in the range of 1.6 to 1.9 and SCB values in the range of 2.2 to 2.6 for the VAS-pain instrument in a nonshoulder hand and upper extremity postoperative population. CLINICAL RELEVANCE: These MCID and SCB estimates may be useful for powering clinical studies and when interpreting VAS-pain score changes or differences reported in the hand surgery literature. These values are to be applied at a population level, and should not be applied to assess the improvement, or lack thereof, for individual patients.

Establishing the Substantial Clinical Benefit in a Non-Shoulder Hand and Upper Extremity Population for the QuickDASH and PROMIS Upper Extremity and Physical Function Computer Adaptive Tests.

PURPOSE: It is unclear what score changes on the abbreviated Disabilities of the Arm, Hand, and Shoulder (QuickDASH), Patient-Reported Outcomes Measurement Information System (PROMIS) upper extremity (UE) computer adaptive test (CAT), and PROMIS physical function (PF) CAT represent a substantial improvement. We calculated the substantial clinical benefit (SCB) for these 3 instruments in a non-shoulder hand and upper extremity population. METHODS: Adult patients treated between March 2015 and September 2019 at a single academic tertiary institution were identified. The QuickDASH, PROMIS UE CAT v2.0, and PROMIS PF CAT v2.0 scores were collected using a tablet computer. Responses to the QuickDASH both at baseline and follow-up 6 ± 4 weeks later, and a response to the anchor question "Compared to your first evaluation at the University Orthopaedic Center, how would you describe your physical function level now?" were required for inclusion. A second anchor question querying treatment-related improvement was also used. The SCB was calculated using an anchor-based approach comparing the mean change difference between groups reporting no change and a maximal change for both anchor questions. RESULTS: Of 1,119 included participants, the mean age was 48 ± 17 years, 53% were women, and half were recovering from surgery. Score changes between baseline and follow-up were significantly different between groups reporting no improvement and maximal improvement on both anchor questions. The SCB values ranged between 16.9 and 22.8 on the QuickDASH, 5.9 and 7.1 on the UE CAT, and 3.5 and 6.7 on the PF CAT. CONCLUSIONS: These score improvements for the QuickDASH, UE CAT, and PF CAT represent a substantial clinical improvement in a non-shoulder hand and upper extremity population. CLINICAL RELEVANCE: These SCB estimates may assist with the interpretation of outcome scores at a population level.

Regional differences between superficial and deep lumbar multifidus in patients with chronic lumbar spine pathology.

BACKGROUND: Due to its unique arrangement, the deep and superficial fibers of the multifidus may have differential roles for maintaining spine stabilization and lumbar posture; the superficial multifidus is responsible for lumbar extension and the deep multifidus for intersegmental stability. In patients with chronic lumbar spine pathology, muscle activation patterns have been shown to be attenuated or delayed in the deep, but not superficial, multifidus. This has been interpreted as pain differentially influencing the deep region. However, it is unclear if degenerative changes affecting the composition and function of the multifidus differs between the superficial and deep regions, an alternative explanation for these electrophysiological changes. Therefore, the goal of this study was to investigate macrostructural and microstructural differences between the superficial and deep regions of the multifidus muscle in patients with lumbar spine pathology. METHODS: In 16 patients undergoing lumbar spinal surgery for degenerative conditions, multifidus biopsies were acquired at two distinct locations: 1) the most superficial portion of muscle adjacent to the spinous process and 2) approximately 1 cm lateral to the spinous process and deeper at the spinolaminar border of the affected vertebral level. Structural features related to muscle function were histologically compared between these superficial and deep regions, including tissue composition, fat fraction, fiber cross sectional area, fiber type, regeneration, degeneration, vascularity and inflammation. RESULTS: No significant differences in fat signal fraction, muscle area, fiber cross sectional area, muscle regeneration, muscle degeneration, or vascularization were found between the superficial and deep regions of the multifidus. Total collagen content between the two regions was the same. However, the superficial region of the multifidus was found to have less loose and more dense collagen than the deep region. CONCLUSIONS: The results of our study did not support that the deep region of the multifidus is more degenerated in patients with lumbar spine pathology, as gross degenerative changes in muscle microstructure and macrostructure were the same in the superficial and deep regions of the multifidus. In these patients, the multifidus is not protected in order to maintain mobility and structural stability of the spine.

Revision of Recalled Modular Neck Rejuvenate and ABG Femoral Implants.

Modular neck femoral stems have been associated with adverse local tissue reactions (ALTR), leading to a voluntary recall, but these effects have not been well-characterized. A retrospective review of intraoperative findings and cobalt/chromium levels was performed in 103 hips undergoing revision for ALTR. The average preoperative serum cobalt level was 7.6 µg/L (range 1.1-23 µg/L) and chromium level was 1.8 µg/L (range 0.1-6.8 µg/L). Metallic sludge was noted in 100%, synovitis in 98%, pericapsular rind in 82%, and calcar erosion in 85%. An osteotomy was required for removal in 44%. We concluded that revision of modular neck femoral stems is associated with increased preoperative metal ion levels and stem-neck corrosion. Despite advanced stem explantation techniques, osteotomy was frequently required, leading to increased morbidity.

MRI Findings Associated with Recalled Modular Femoral Neck Rejuvenate and ABG Implants.

MARS-MRI is suggested for the diagnosis of adverse local tissue reactions (ALTR) in patients with recalled femoral stems with modular necks, but there has been no major study looking at MARS-MRI findings in this population. A retrospective review was performed on 312 patients who received a modular neck hip implant between October 2007 and February 2012. 62% of patients had intra-articular effusions, with 27% containing debris. Extra-capsular effusions were present in 35% of hips. 54% had synovitis and 5.4% had osteolysis. Tendinopathy and tendon disruption was present in the gluteus medius (58%/12%), hamstring (56%/12%), gluteus minimus (38%/7.7%) and iliopsoas (7.1%/4.8%). Abnormal MARS-MRI findings are associated with modular neck femoral components and can suggest underlying ALTR. MARS-MRI abnormalities merit serious consideration in this population.

Recurrent Carpal Tunnel Syndrome Associated with Mycobacterium szulgai Infection: A Case Report.

CASE: We present the case of an otherwise healthy 77-year-old male retired firefighter and recreational pheasant hunter who presented with recurrent symptoms of carpal tunnel syndrome and tenosynovitis because of Mycobacterium szulgai. He was initially treated unsuccessfully for a presumed seronegative rheumatologic flare, followed by surgical diagnosis and treatment including revision carpal tunnel release with tenosynovectomy, and a secondary debridement and wound closure. His symptoms resolved after several months of multidrug antibiotic therapy with only mild residual median nerve deficit. CONCLUSION: Nontuberculous Mycobacterium infections of the upper extremity are extremely rare and challenging to diagnose/treat. This report highlights diagnostic and surgical challenges in this rarely reported infection.

Contribution of Lumbar Spine Pathology and Age to Paraspinal Muscle Size and Fatty Infiltration.

STUDY DESIGN: Retrospective chart analysis of 199 individuals aged 18 to 80 years scheduled for lumbar spine surgery. OBJECTIVE: The purpose of this study was to quantify changes in muscle cross-sectional area (CSA) and fat signal fraction (FSF) with age in men and women with lumbar spine pathology and compare them to published normative data. SUMMARY OF BACKGROUND DATA: Pathological changes in lumbar paraspinal muscle are often confounded by age-related decline in muscle size (CSA) and quality (fatty infiltration). Individuals with pathology have been shown to have decreased CSA and fatty infiltration of both the multifidus and erector spinae muscles, but the magnitude of these changes in the context of normal aging is unknown. METHODS: Individuals aged 18 to 80 years who were scheduled for lumbar surgery for diagnoses associated with lumbar spine pain or pathology were included. Muscle CSA and FSF of the multifidus and erector spinae were measured from preoperative T2-weighted magnetic resonance images at the L4 level. Univariate and multiple linear regression analyses were performed for each outcome using age and sex as predictor variables. Statistical comparisons of univariate regression parameters (slope and intercept) to published normative data were also performed. RESULTS: There was no change in CSA with age in either sex (P > 0.05), but women had lower CSAs than men in both muscles (P < 0.0001). There was an increase in FSF with age in erector spinae and multifidus muscles in both sexes (P < 0.0001). Multifidus FSF values were higher in women with lumbar spine pathology than published values for healthy controls (P = 0.03), and slopes tended to be steeper with pathology for both muscles in women (P < 0.08) but not in men (P > 0.31). CONCLUSION: Lumbar muscle fat content, but not CSA, changes with age in individuals with pathology. In women, this increase is more profound than age-related increases in healthy individuals. LEVEL OF EVIDENCE: 3.

Lumbar multifidus muscle degenerates in individuals with chronic degenerative lumbar spine pathology.

Histological and cell-level changes in the lumbar musculature in individuals with chronic lumbar spine degenerative conditions are not well characterized. Although prior literature supports evidence of changes in fiber type and size, little information exists describing the tissue quality and biology of pathological features of muscle in this population. The purpose of this study was to quantify multifidus tissue composition and structure, inflammation, vascularity, and degeneration in individuals with chronic degenerative lumbar spine pathology. Human multifidus biopsies were acquired from 22 consecutive patients undergoing surgery for chronic degenerative lumbar spine pathology. Relative fractions of muscle, adipose, and extracellular matrix were quantified along with muscle fiber type and cross-sectional area (CSA) and markers of inflammation, vascularity, satellite cell density, and muscle degeneration. On average, multifidus biopsies contained 48.5% muscle, 11.7% adipose tissue, and 26.1% collagen tissue. Elevated inflammatory cell counts (48.5 ± 30.0 macrophages/mm2 ) and decreased vascularity (275.6 ± 69.4 vessels/mm2 ) were also observed compared to normative values. Satellite cell densities were on average 13 ± 9 cells per every 100 muscle fibers. Large fiber CSA (3,996.0 ± 1,909.2 µm2 ) and a predominance of type I fibers (61.8 ± 18.0%) were observed in addition to evidence of pathological degeneration-regeneration cycling (18.8 ± 9.4% centrally nucleated fibers, and 55.2 ± 24.2% of muscle regions containing degeneration). High levels of muscle degeneration, inflammation, and decreased vascularity were commonly seen in human multifidus biopsies of individuals with lumbar spine pathology in comparison to normative data. Evidence of active muscle degeneration suggests that changes in muscle tissue are more complex than simple atrophy. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2700-2706, 2017.