Radiographic Description of Soft Tissue Attachments around the Elbow.

Objectives: Quantitatively define the radiographic locations of the major soft-tissue attachments about the elbow. Methods: In 10 cadaveric elbows, the attachments of the medial ulnar collateral ligament, lateral ulnar collateral ligament, annular ligament, triceps, and biceps were marked with radiopaque spheres. Measurements were made on calibrated AP and lateral fluoroscopic images from known osseous landmarks. Results: On AP radiographs; the anterior bundle of the MUCL (aMUCL) measured 28.6mm (95% CI, 27. 5-29.8mm) from the humeral attachment to the midpoint of the MUCL ridge on the ulna and 14.3mm, (95% CI 13.0-15.5) to the olecranon. The LUCL was 39.9mm (95% CI, 38.6 - 41.1mm) from the humeral attachment to the supinator crest attachment and 8.9mm (95% CI, 8.1-9.8mm) to the lateral epicondyle. On the lateral radiographs, the humeral attachment of the aMUCL to the medial coronoid was 27.1mm (95% CI, 25.9-28.2mm) and 9.3mm (95%CI, 17.5 -21.2mm) to the tip. The LUCL humeral attachment to the supinator crest was 45.4mm (95%CI, 44.1-46.8mm). The LUCL humeral attachment was located 8.9mm (95%CI, 8.0-9.7mm) posterior from the anterior humeral line. Conclusion: The soft-tissue attachments about the elbow were reproducibly demonstrated on radiographs in relation to osseous landmarks and radiographic lines. The radiographic relationships will allow for improved identification of the ligament and tendon attachment sites of the elbow for intraoperative assessment and postoperative evaluation following reconstruction.

Humeral loosening in reverse shoulder arthroplasty: an analysis of 2,342 cases.

INTRODUCTION: Humeral loosening is a rare complication in reverse shoulder arthroplasty (RSA) representing approximately 1% of total complications. The purpose of this study is to identify patients who underwent RSA and were revised because of loosening of the humeral component, identify patients who are at increased risk, and report on their surgical outcomes. MATERIALS AND METHODS: A retrospective review of all patients who received a primary RSA or revision RSA (rRSA) by a single surgeon from 2002-2021 identified a total of 1591 primary RSA and 751 rRSA procedures. These procedures were then organized based on indication for surgery. Further analysis was performed to identify RSAs that were subsequently revised because of aseptic loosening of the humeral component. A total of 41 surgeries met the inclusion criterion for the study, which was any RSA or rRSA that was revised because of loosening of the humeral component. Exclusion criterion was revision for a reason other than humeral loosening, neurogenic arthritis, or revision for loosening that was not originally implanted by the senior author (9 surgeries). Ultimately, 32 surgeries met criteria for further analysis. These 32 surgeries were organized by indication for preceding RSA or rRSA and were assessed for an association between indication for RSA or rRSA and eventual revision for humeral loosening. Additionally, these procedures were compared to a "control cohort" of procedures that were not revised and that had minimum 2 years' follow-up. To assess outcomes for these patients, pre- and postoperative Simple Shoulder Test, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and ranges of motion were compared. Twenty procedures had sufficient data for outcomes analysis and were followed for an average of 54 months (range: 24-132 months). RESULTS: In primary RSAs, procedures performed for fracture or fracture sequelae were associated with revision for humeral-sided loosening (P = .009). In rRSAs, procedures performed for failed hemiarthroplasty for CTA were associated with rerevision for humeral-sided loosening (P = .009). Nine percent of patients revised for humeral loosening required rerevision for recurrent humeral loosening. Analysis of patients with 2-year clinical follow-up for humeral-sided loosening showed improvement in ASES pain (P = .014), ASES function (P = .042), and total ASES scores (P = .007). CONCLUSION: Humeral loosening is rare in RSA. In our cohort, 0.7% of the primary RSAs performed and 2.8% of the rRSAs performed were eventually revised for humeral loosening. Revisions of RSA for humeral loosening yield modest clinical improvements. Rerevision for humeral loosening was 6.3% of patients in our cohort.

Outcomes of femoral head allograft for the management of glenoid bone defects in revision reverse shoulder arthroplasty: a case-controlled study.

BACKGROUND: Revision shoulder arthroplasty often requires management of glenoid bone defects. Options include using allograft, harvesting iliac crest autograft, or using augmented metal components. The purpose of this study is to report outcomes of revision shoulder arthroplasty requiring management of glenoid bone defects with femoral head allograft in a large cohort of patients using a single reverse shoulder implant system and compare them to a matched cohort based on the indication for surgery. Outcomes of patients who had successful glenoid reconstruction were compared to those that required a re-revision, and to a control group that was revised without the need for bone graft. METHODS: This was a retrospective review of data collected from 2009 to 2018. There were 36 patients in the bone graft group and 52 in the control group. All patients underwent revision to a reverse shoulder arthroplasty to manage a failed total shoulder arthroplasty (n = 29 and 11), hemiarthroplasty (n = 1 and 24), or reverse shoulder arthroplasty (n = 6 and 17). All patients had a minimum of 2 yr of clinical follow-up. The primary endpoint was survival of baseplate fixation. Secondary outcomes included range of motion and functional outcome scores. Patients that had recurrent baseplate failure and were re-revised were compared to patients with bone graft that did not require additional surgery, and to patients who were revised without the need for bone graft. Patients who required revisions for reasons other than recurrent baseplate failure were also recorded. RESULTS: Five of 36 (14%) patients had recurrent baseplate failure. Mean time to failure was 12 mo. Three of 5 had successful re-implantation of another baseplate. Two of 5 were revised to a hemi arthroplasty after failure of their revisions. Preoperative American Shoulder and Elbow Surgeons scores were 31 in the grafted patients that did not require re-revision, 39 in the grafted patients that required re-revision, and 33 in the control group. Final American Shoulder and Elbow Surgeons scores were 64, 36, and 56, respectively. One patient required revision surgery not related to baseplate failure. There were no baseplate failures in the control group. CONCLUSION: The use of femoral head allograft to manage glenoid bone defects in the revision setting produces predictable improvement in functional outcomes that is not inferior to those in patients revised without bone graft. However, there is a 14% rate of baseplate failure.

Epidemiology of congenital upper limb anomalies in a midwest United States population: an assessment using the Oberg, Manske, and Tonkin classification.

PURPOSE: To examine the relative presentation frequency of children with upper limb congenital anomalies at 3 Midwestern referral centers using the Oberg, Manske, and Tonkin (OMT) classification and to assess the utility of this new classification system. METHODS: 641 individuals with 653 congenital upper extremity anomalies were identified at 3 hospitals in 2 large metropolitan areas during a 1-year interval. Patients were identified prospectively and the specific upper extremity anomaly and any associated syndromes were confirmed using medical records and radiographs. We applied the OMT classification that categorizes anomalies using a dysmorphology outline as malformations, dysplasias, deformations, and syndromes, and assessed its utility and ease of use. RESULTS: There were 480 extremities (74%) with a limb malformation including 184 involving the entire limb. Arthrogryposis was the most common of these (53 extremities). Anomalies affecting only the hand plate accounted for 62% (296) of the malformations. Of these, radial polydactyly (15%) was the most common specific anomaly, followed by symbrachydactyly (13%) and cleft hand (11%). Dysplasias were noted in 86 extremities; 55 of these were multiple hereditary exostoses. There were 87 extremities with deformations and 58 of these were trigger digits. A total of 109 children had a syndrome or association. Constriction ring sequence was most common. The OMT was straightforward to use and most anomalies could be easily assigned. There were a few conditions, such as Madelung deformity and symbrachydactyly, that would benefit from clarification on how to best classify them. CONCLUSIONS: Malformations were the most common congenital anomalies in the 653 upper extremities evaluated over a 1-year period at 3 institutions. We were able to classify all individuals using the OMT classification system.

Evidence that highly conserved residues of transmembrane segment 6 of Escherichia coli MntH are important for transport activity.

Nramp (natural resistance-associated macrophage protein) family members have been characterized in mammals, yeast, and bacteria as divalent metal ion/H(+) symporters. In previous work, a bioinformatic approach was used for the identification of residues that are conserved within the Nramp family [Haemig, H. A., and Brooker, R. J. (2004) J. Membr. Biol. 201 (2), 97-107]. On the basis of site-directed mutagenesis of highly conserved negatively charged residues, a model was proposed for the metal binding site of the Escherichia coli homologue, MntH. In this study, we have focused on the highly conserved residues, including two histidines, of transmembrane segment 6 (TMS-6). Multiple mutants were made at the eight conserved sites (i.e., Gly-205, Ala-206, Met-209, Pro-210, His-211, Leu-215, His-216, and Ser-217) in TMS-6 of E. coli MntH. Double mutants involving His-211 and His-216 were also created. The results indicate the side chain volume of these residues is critically important for function. In most cases, only substitutions that are closest in side chain volume still permit transport. In addition, the K(m) for metal binding is largely unaffected by mutations in TMS-6, whereas V(max) values were decreased in all mutants characterized kinetically. Thus, these residues do not appear to play a role in metal binding. Instead, they may comprise an important face on TMS-6 that is critical for protein conformational changes during transport. Also, in contrast to other studies, our data do not strongly indicate that the conserved histidine residues play a role in the pH regulation of metal transport.