ABSTRACT
BACKGROUND: Bat swing and grip type may contribute to hook of hamate fractures in baseball players. PURPOSE: To compare the effects of swing type and batting grip on the pressure and rate of pressure development over the hook of hamate in collegiate baseball players. STUDY DESIGN: Descriptive laboratory study. Level of evidence, 3. METHODS: This was an experimental quasi-randomized study of bat grip and swing differences in National Collegiate Athletic Association Division I baseball players (N = 14; age, 19.6 ± 1.1 years [mean ± SD]). All participants performed swings under 6 combinations: 3 grip types (all fingers on the bat shaft [AO], one finger off the bat shaft [OF], and choked up [CU]) and 2 swing types (full swing and check swing). Peak pressure and rate of pressure generation over the area of the hamate were assessed using a pressure sensor fitted to the palm of the bare hand over the area of the hamate. Wrist angular velocities and excursions of radial ulnar deviation were obtained using 3-dimensional motion analysis. RESULTS: The OF-check swing combination produced the highest peak pressure over the hamate (3.72 ± 2.64 kg/cm2) versus the AO-full swing (1.36 ± 0.73 kg/cm2), OF-full swing (1.68 ± 1.17 kg/cm2), and CU-full swing (1.18 ± 0.96 kg/cm2; P < .05 for all). There was a significant effect of condition on rate of pressure development across the 6 conditions (P = .023). Maximal wrist angular velocities were 44% lower in all check swing conditions than corresponding full swing conditions (P < .0001). The time to achieve the maximal wrist angular velocity was longest with the AO-full swing and shortest with the CU-check swing (100.1% vs 7.9% of swing cycle; P = .014). CONCLUSION: The OF-check swing condition produced the highest total pressure reading on the hook of hamate. Check swing conditions also had the steepest rate of pressure development as compared with the full swing conditions. CLINICAL RELEVANCE: Batters who frequently check their swings and use an OF or AO grip may benefit from bat modifications or grip adjustment to reduce stresses over the hamate. Athletic trainers and team physicians should be aware of these factors to counsel players in the context of previous or ongoing hand injury.
ABSTRACT
BACKGROUND: No studies compare outcomes of anatomic total shoulder arthroplasty to reverse total shoulder arthroplasty with more than five-year follow-up. METHODS: A multicenter prospectively collected shoulder registry was utilized to review all patients undergoing primary anatomic total shoulder arthroplasty or primary reverse total shoulder arthroplasty with a minimum five-year follow-up utilizing a single platform stem implant system. One-hundred-ninety-one patients received an anatomic total shoulder arthroplasty and 139 patients received a reverse total shoulder arthroplasty. Patients were scored preoperatively and at latest follow-up using the simple shoulder test (SST), University of California Los Angeles (UCLA), American shoulder and elbow surgeons (ASES), Constant, and shoulder pain and disability index (SADI) scores as well as range of motion. Radiographs were evaluated for implant loosening or notching. Complications were reviewed. A Student's two-tailed, unpaired t-test identified differences in preoperative, postoperative, and pre-to-postoperative improvements. RESULTS: Reverse total shoulder arthroplasty patients were significantly older than anatomic total shoulder arthroplasty patients. All patients demonstrated significant improvement in functional metric scores and range of motion following anatomic total shoulder arthroplasty or reverse total shoulder arthroplasty. There was no difference in final outcome scores between anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty patients at midterm follow-up; however, reverse total shoulder arthroplasty patients demonstrated significantly less motion. DISCUSSION: We demonstrate equivalent outcomes with five scoring metrics at mean follow-up of 71.3 ± 14.1 months. Although postoperative scores were significantly greater than preoperative scores for both anatomic total shoulder arthroplasty and reverse total shoulder arthroplasty patients, significant differences in outcome scores between cohorts were not observed.
ABSTRACT
Quadrilateral space (QS) syndrome (QSS) is a relatively rare condition in which the axillary nerve and the posterior humeral circumflex artery are compressed within the QS. Fibrous bands are most commonly implicated as the cause, with true space-occupying lesions being less common. QSS is characterized by poorly localized shoulder pain and paresthesia over the lateral aspect of the shoulder and arm in a nondermatomal pattern. These symptoms are aggravated by shoulder abduction and external rotation. Point tenderness is typically present over the QS; however, diagnosis on physical examination can be difficult. Pain relief after lidocaine block of the axillary nerve within the QS is a useful finding in the evaluation of patients with suspected QSS. No definitive diagnostic imaging exists, making diagnosis difficult, although radiographs and magnetic resonance imaging are recommended to rule out other pathology. Nonoperative treatment, including nonsteroidal anti-inflammatory drugs, activity modification, and physical therapy, for at least 6 months is recommended before pursuing operative intervention. Small case series have shown that surgical decompression of the QS has good outcomes, with resolution of pain and return to sport.
