Effect of Radiocapitellar Joint Over/Under Stuffing on Elbow Joint Contact Pressure.

PURPOSE: Comminuted radial head fractures are commonly treated by surgical resection or replacement with a prosthesis. A potential problem with radial head replacement is overlengthening of the radial neck ("overstuffing" of the radial head), which has been shown to affect both ulnohumeral kinematics and radiocapitellar pressures. We hypothesized that an overstuffed radial head prosthesis increases capitellar pressure and reduces coronoid pressure. METHODS: Seven human cadaveric elbows were prepared on a custom-designed apparatus simulating stabilizing muscle loads, and passively flexed from 0° to 90° under gravity valgus torque while joint contact pressures were measured. Each elbow was tested sequentially with different neck lengths, starting with the intact specimen followed by insertion of understuffed (-2 mm), standard-height (0 mm), and overstuffed (+2 mm) radial head prostheses in neutral forearm rotation, 40° pronation, and 40° supination positions, respectively. RESULTS: Capitellar mean contact pressures significantly increased after insertion of an overstuffed radial head prosthesis. In valgus position with neutral forearm rotation, capitellar mean contact pressure on the joint with an intact radial head averaged 227 ± 70 kPa. Insertion of understuffed, standard-height, and overstuffed radial head prostheses changed the mean contact pressures to 152 ± 76 kPa, 212 ± 68 kPa, and 491 ± 168 kPa, respectively. The overstuffed radial head group had significantly lower whole coronoid mean contact pressures (153 ± 56 kPa) compared with the intact (390 ± 138 kPa) and standard-height (376 ± 191 kPa) radial head groups. CONCLUSIONS: An increase in radial prosthesis height significantly increases capitellar contact pressures and reduces coronoid contact pressures. CLINICAL RELEVANCE: Restoration of the anatomic radial head height is critical when performing radial head arthroplasty to maintain normal joint biomechanics. Elevated capitellar contact pressures can potentially lead to pain and early degenerative changes.

Prospective Randomized Trial of Continuous Passive Motion Versus Physical Therapy After Arthroscopic Release of Elbow Contracture.

BACKGROUND: Continuous passive motion (CPM) has been used for decades, but we are not aware of any randomized controlled trials (RCTs) in which CPM has been compared with physical therapy (PT) for rehabilitation following release of elbow contracture. METHODS: In this single-blinded, single-center RCT, we randomly assigned patients undergoing arthroscopic release of elbow contracture to a rehabilitation protocol involving either CPM or PT. The primary outcomes were the rate of recovery and the arc of elbow motion (range of motion) at 1 year. The rate of recovery was evaluated by measuring range of motion at 6 weeks and 3 months. The secondary outcomes included other range-of-motion-related outcomes, patient-reported outcome measures (PROMs), flexion strength and endurance, grip strength, and forearm circumference at multiple time points. RESULTS: A total of 24 patients were assigned to receive CPM, and 27 were assigned to receive PT. At 1 year, CPM was superior to PT with regard to the range of motion, with an estimated treatment difference of 9° (95% confidence interval [CI], 3° to 16°; p = 0.007). Similarly, the use of CPM led to a greater range of motion at 6 weeks and 3 months than PT. The percentage of lost motion recovered at 1 year was higher in the CPM group (51%) than in the PT group (36%) (p = 0.01). The probability of restoring a functional range of motion at 1 year was 62% higher in the CPM group than in the PT group (risk ratio for functional range of motion, 1.62; 95% CI, 1.01 to 2.61; p = 0.04). PROM scores were similar in the 2 groups at all time points, except for a difference in the American Shoulder and Elbow Surgeons (ASES) elbow function subscale, in favor of CPM, at 6 weeks. The use of CPM decreased swelling and reduced the loss of flexion strength, flexion endurance, and grip strength on day 3, with no between-group differences thereafter. CONCLUSIONS: Among patients undergoing arthroscopic release of elbow contracture, those who received CPM obtained a faster recovery and a greater range of motion at 1 year, with a higher chance of restoration of functional elbow motion than those who underwent routine PT. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Smartphone "Selfies"-A reliable and accurate tool for measuring elbow range of motion.

BACKGROUND: To determine if self-taken photographs ("selfies"), performed independently after instruction by video or illustrated handout, would be an accurate and reliable tool for capturing elbow range of motion in patients with elbow contractures. METHODS: Fifty patients presenting with elbow contractures participated in the study. After completion of the selfie, the senior author clinically measured flexion and extension with a goniometer. The angles from the photographs were measured and analyzed. RESULTS: The agreement between goniometer and "selfie" measurements correlated closely (R2 = 0.98) and agreement was excellent in both extension and in flexion with intra-class correlation coefficients of 0.95 (95% CI 0.92 to 0.97) in extension with a mean difference of 2° (95% CI -3° to 7°), and 0.93 (95% CI 0.89 to 0.96) in flexion with a mean difference of 4° (95% CI 0° to 8°). Systematic errors were low in extension, 0° (95% CI, ±11°) and in flexion -3° (95% CI, ±10°). Six patients demonstrated ≥10° difference between clinical and selfie measurements. Ability to take a usable selfie was inversely correlated with age (R2 = 0.97). DISCUSSION: Self-taken flexion-extension photographs are a reliable and accurate tool for measuring elbow range of motion. Errors in the selfie technique are well tolerated and appear to have a negligible effect upon measurements of motion. This important parameter of elbow function can therefore be obtained outside a normal clinic visit, thereby improving frequency of follow-up assessments (and minimizing loss to follow-up) necessary for quality control and research.

Effect of incremental increase in radial neck height on coronoid and capitellar contact pressures.

BACKGROUND: Over-lengthening of the radial neck has been shown to affect ulnohumeral kinematics and has been proposed to affect radiocapitellar pressures. We hypothesized that an incremental increase in radial neck height increases the capitellar contact pressure and reduces the coronoid contact pressure. Knowledge of the effects of over-lengthening is clinically important in preventing pain and degenerative changes due to overstuffing. METHODS: Six human cadaveric elbows were prepared on a custom-designed apparatus simulating muscle loads and passive flexion from 0° to 90° under gravity valgus torque while measuring joint contact pressures in this biomechanical study. Each elbow was tested sequentially starting with the intact specimen followed by insertion of a radial head prosthesis with 0, +2, and +4 mm of radial neck height, respectively. RESULTS: Capitellar mean contact pressures significantly increased after insertion of +2 and +4 mm radial head prostheses (p < 0.03). The capitellar mean contact pressure with a 0 mm radial head prosthesis was 97 KPa. Insertion of +2 mm and +4 mm radial heads increased mean contact pressures to 391 KPa (p = 0.001) and 619 KPa (p = 0.001), respectively, with 90° of elbow flexion. DISCUSSION: Increasing radial prosthesis height by 2 mm significantly increases capitellar contact pressures and reduces coronoid contact pressures.

Patients Use Fewer Opioids Than Prescribed After Arthroscopic Release of Elbow Contracture: An Evidence-Based Opioid Prescribing Guideline to Reduce Excess.

PURPOSE: To generate an evidence-based opioid-prescribing guideline by assessing the pattern of total opioid consumption and the factors that may predict opioid consumption following arthroscopic release of elbow contracture and to investigate whether the use of continuous passive motion (CPM), as compared to physical therapy (PT), was associated with a decrease in pain and opioid consumption after arthroscopic release of elbow contracture. METHODS: Data collected from a randomized controlled trial that compared continuous passive motion (CPM) (n = 24) to physical therapy (PT) (n = 27) following arthroscopic release of elbow contracture was analyzed for opioid use. Fifty-one participants recorded their daily opioid consumption in a postoperative diary for 90 days. Multivariate analysis was performed to identify factors associated with opioid use. Recommended quantities for postoperative prescription were generated using the 50th percentile for patients without and the 75th percentile for patients with factors associated with higher opioid use. RESULTS: The median total opioid prescription was 437.5-mg morphine milligram equivalents (MMEs) (58 pills of 5 mg oxycodone) and the median total opioid consumption was 75 MMEs (10 pills of 5-mg oxycodone). Twenty-two percent of patients took no opioid medication, 53% took ≤10 pills, 69% took ≤20 pills and 75% took ≤30 pills. Predictors of higher opioid use were preoperative opioid use, age <60 years and inflammatory arthritis. The total opioid consumption appeared similar between the CPM and the PT group. Seventy-five percent of patient's home opioid requirements would be satisfied using the following guideline: Patients undergoing contracture release for osteoarthritis or post-traumatic contracture should be given a prescription for 10 pills of 5 mg oxycodone or its equivalent at discharge. Patients with inflammatory conditions or those taking preoperative opioids should be prescribed 30 pills of 5 mg oxycodone or its equivalent. CONCLUSION: This study suggests that most patients undergoing arthroscopic release of elbow contracture use relatively few opioid pills after surgery. Use of an evidence-based guideline could decrease opioid prescriptions substantially, while still effectively treating patients' pain.

Prospective Blinded Evaluation of Patient-Physician Agreement Using the Summary Outcome Determination (SOD) Score.

OBJECTIVE: To determine whether the Summary Outcome Determination (SOD) score demonstrates a high level of physician-patient agreement in a prospective setting with multiple raters. PATIENTS AND METHODS: For this study, 100 patients who were being evaluated at various intervals following shoulder or elbow surgery were prospectively enrolled from May 30, 2017, through August 31, 2017. The patients' attending physicians and a member of their team (physician assistant, resident, fellow, medical student) assigned categorical and numerical SOD scores while blinded to the scores given by each other. All scores were analyzed among raters, assessing internal consistencies, agreement, and reliability. RESULTS: The mean follow-up (interval between surgery and completion of the survey) was 31 months, with a range of 1 to 220 months. The intraclass correlation coefficient for patient and physician numerical scores was excellent at 0.82. The weighted κ value for categorical scores was 0.64. Bland-Altman analysis revealed low average discrepancy at 0.6 with a 95% CI of -3.3 to 4.5. The Cronbach α value was 0.94, indicating strong internal validity. The categorical physician-patient agreement occurred within one category 96% of the time. CONCLUSION: This study found that the SOD score has strong agreement with excellent intraclass correlation coefficient and weighted κ values, indicating substantial agreement, reproducibility (shown by low average error), and strong internal validity. With promising results in the prospective setting, the SOD score was found to be an easy to use outcome measure with reliable agreement between patient and physician. This score has potential to be a metric revealing the "value" of a specific surgical intervention.

Component fracture after total elbow arthroplasty.

BACKGROUND: Ulnar or humeral component stem fractures after total elbow arthroplasty (TEA) are serious complications. We hypothesized that TEA stem component fractures are fatigue fractures that result from periarticular osteolysis caused by bushing wear, which leads to a region of unsupported stem adjacent to a region where the stem is well-fixed. METHODS: A review of 2637 primary and revision TEA cases from 1972 to 2016 revealed that 47 operations in 46 patients were complicated by or performed to deal with component stem fractures. Bushing wear was graded according to percentage loss of polyethylene thickness and metal wear. RESULTS: In the 39 cases in which bushing wear was able to be quantitated, it was severe in 34, moderate in 2, and mild in 3. Radiographs at final follow-up were available in 47 cases. All 47 cases showed evidence of periarticular osteolysis, which was in zone 1 in 17, in zones 1 and 2 in 29, and diffuse in 1. The length of the well-fixed stem, expressed as a percentage of total stem length, averaged 63% (range, 29%-86%). Stem fractures most often (27 of 47 cases) occurred at the junction between the well-fixed stem and unsupported stem. The median distance between the site of stem fracture and the unsupported-well-fixed stem junction was 0 mm (interquartile range, 0-5 mm). CONCLUSION: On the basis of our findings, a component stem fracture after TEA seems to occur by fatigue failure at or near the junction between an unsupported stem and well-fixed stem. This area of unsupported stem occurs as a result of osteolysis caused by bushing wear. The solution for component fractures requires a solution for bushing wear.

Long-term outcome of custom triflange outrigger ulnar component in revision total elbow arthroplasty.

BACKGROUND: Patients missing the distal humeral condyles are prone to premature bushing wear after total elbow arthroplasty. A midterm study has demonstrated that a custom triflange outrigger ulnar component was successful in preventing this. The aim of this study was to determine whether these results remained stable over time. MATERIALS AND METHODS: The outcomes of 6 patients who underwent revision of a loose ulnar component using a custom triflange outrigger component were reviewed in this retrospective case study. The average patient age at the time of revision was 51. The average number of prior operations was 2 (range, 1-3). The mean follow-up was 15 years (range, 10-18 years). RESULTS: At final follow-up, the mean range of extension-flexion was 35° to 135°, and pronation-supination was 65° to 63°. The average Mayo Elbow Performance Score improved to 75 of 100. Four implants were still in place with no radiolucencies or osteolysis. Three patients required revision surgery for broken humeral stems. Two required conversion to another total elbow arthroplasty system after 18 and 14 years for humeral component loosening. CONCLUSIONS: These components lasted an average of 4 times longer than the original ulnar components. In our experience, periarticular osteolysis caused by polyethylene wear creates a region of unsupported stem and a stress riser at the junction with the remaining well-supported stem and causes component stem fractures. The concept of an outrigger type of hinge might be useful for active patients requiring an elbow prosthesis in the setting of deficient condyles.

Effect of radiocapitellar Achilles disc arthroplasty on coronoid and capitellar contact pressures after radial head excision.

BACKGROUND: Long-term radiographic arthritis has been commonly reported after radial head excision. Concern over radial head arthroplasty may arise in certain situations including capitellar arthritis, radiocapitellar malalignment, and in young and active patients. We hypothesized that radial head excision increases coronoid contact pressures, which may at least be partially reduced by radiocapitellar Achilles tendon disc arthroplasty. METHODS: Coronoid and capitellar contact pressure was measured on 6 human cadaveric elbows on a custom-designed gravity-valgus simulator under passive flexion from 0° to 90°. Sequential testing, starting with the intact specimen, resection of the radial head, and finally, radiocapitellar Achilles tendon disc arthroplasty were performed on each specimen. RESULTS: Mean contact pressure of the coronoid significantly increased after radial head excision (P < .0001) and significantly improved after Achilles disc arthroplasty (P < .0001). The pressure difference was most pronounced on the lateral coronoid. From 15° to 85° of elbow flexion, mean contact pressures on the lateral coronoid were 291 kPa and 476 kPa before and after radial head excision, respectively (P < .0001). Achilles disc arthroplasty significantly lowered coronoid contact pressures to 385 kPa (P = .002); however, they remained significantly higher than those in the intact radial head group (P = .0009). CONCLUSIONS: Radial head resection increases contact pressure in the coronoid, especially the lateral coronoid. This study showed that radiocapitellar Achilles disc arthroplasty significantly improves contact pressures on the coronoid after radial head resection. Achilles disc arthroplasty could be considered in patients who are not candidates for radial head arthroplasty.

Patient-Physician Agreement Using Summary Outcome Determination Scores.

OBJECTIVE: To determine whether the Summary Outcome Determination (SOD) score had exhibited a high level of physician-patient agreement in surgical patients. PATIENTS AND METHODS: The medical records of 320 postoperative patients were reviewed, of whom 164 patients were included in the study. Patients were included if both physician-assigned and patient-assigned SOD scores had been recorded. The SOD is administered as follows: the patient is asked "Compared to before surgery, is your elbow/shoulder better, worse or no different?" If better: "Is it improved, greatly improved, almost normal or normal?" If worse: "Is it worse or profoundly worse, or as bad as dying?" Each category is associated with a numerical value and definition for further clarification. The patient is asked to assign a category and a numerical value after the physician has already done so. These categories and values were evaluated between raters (ie, physician and patient) to assess reliability. RESULTS: The intraclass correlation coefficient of physician-patient numerical ratings was "excellent" (0.93). The Bland-Altman 95% limits of agreement on the differences between the physician and the patient ranged from -1.3 to 1.3. The physician and patient numerical rankings matched exactly in 118 patients (72%) or differed by a factor of no more than 1 (26%) in 161 (98%) patients. CONCLUSION: The SOD score can be used as both a surgeon-based and a patient-based outcome score, given the high level of agreement. Given its brevity, ease of understanding, and high interrater reliability, the SOD has the potential to be used across multiple specialties to rate outcomes.