Surgical Techniques for Correction of Traumatic Hyperextension Instability of the Proximal Interphalangeal Joint: A Biomechanical Study.

PURPOSE: To compare the biomechanical strengths of 5 surgical techniques for treatment of traumatic hyperextension instability of the proximal interphalangeal (PIP) joint. METHODS: Thirty-six cadaveric fingers were randomly assigned to 6 groups: normal control, volar plate repair, flexor digitorum superficialis tenodesis (FDST), single lateral band transfer (SLBT), double lateral band transfer, and dual split lateral band transfer. For each experimental specimen, the volar plate and accessory collateral ligaments were transected, the PIP joint was hyperextended to 90°, and a PIP joint stabilizing procedure was completed. The ultimate strength of each procedure was ascertained by loading to failure, and the fingers were dissected to determine the pathoanatomy of failure. Force-displacement curves were used to estimate the stiffness of each group, and multiple pairwise statistical comparisons were performed. RESULTS: The mean PIP joint stiffness in the control group was significantly greater than the mean PIP joint stiffness in the FDST and SLBT groups, but not significantly different from the mean PIP joint stiffness in the other 3 groups. There were no significant differences in the mean PIP joint stiffness between the 5 joint stabilizing techniques. The SLBT, double lateral band transfer, and dual split lateral band transfer repairs all failed by massive disruption of the flexor tendon sheath, whereas the volar plate repairs and FDST repairs failed by either suture anchor pullout or suture breakage. CONCLUSIONS: The stiffness of 5 surgical techniques to stabilize a traumatic hyperextensible PIP joint did not vary significantly. CLINICAL RELEVANCE: The 5 described techniques to stabilize a posttraumatic PIP joint hyperextension deformity may provide for equal restraint to PIP joint hyperextension instability in the early postoperative period. The choice of procedure should take into consideration other factors not studied, including the potential for PIP joint flexion contracture and long-term durability.

Does Implant Design Influence the Accuracy of Patient Specific Instrumentation in Total Knee Arthroplasty?

PSI software adjusts preoperative planning to accommodate differences in implant design. Such adjustments may influence the accuracy of intraoperative jig placement, bone resection, or component placement. Our purpose was to determine whether implant design influences PSI accuracy. 96 and 123 PSI TKA were performed by a single surgeon using two different implant systems and identical PSI software. Femoral coronal alignment outliers were greater for Implant 1 (23.9% Implant 1 vs. 13.4% Implant 2; P=0.050). Tibial coronal alignment outliers were greater for Implant 2 (10.9% Implant 1 vs. 22.7% Implant 2; P=0.025). There was no difference in overall mechanical axes. Differences in implant design can influence bone resection and component alignment. PSI software rationale must align with surgeons' intraoperative goals.

First carpometacarpal arthroplasty with ligamentous reconstruction: a long-term follow-up.

BACKGROUND: The purpose of the present study is to evaluate a single surgeon's short, intermediate, and long-term clinical, functional, and radiographic outcomes with a trapeziectomy with flexor carpi radialis (FCR) suspension arthroplasty without tendon interposition (LRSA). METHODS: Twenty-one patients underwent 26 FCR suspension arthroplasties without tendon interposition by a single senior surgeon. All patients had Eaton stage III and IV carpometacarpal (CMC) osteoarthritis. The Patient-Rated Wrist and Hand Evaluation (PRWHE) and Quick Disabilities of Arm, Shoulder, and Hand (QuickDASH) were used to evaluate functional outcomes. A comprehensive strength and range of motion evaluation was performed to evaluate clinical outcomes. Plain radiographs at rest and with maximal pinch were performed to evaluate for arthroplasty space subsidence. RESULTS: The LRSA exhibited consistent clinical and functional outcomes throughout postoperative follow-up. As the average patient age and time from surgery increased, range of motion (ROM) and PRWHE scores stayed relatively constant, while lateral tip and tip pinch strength deteriorated with time. The LRSA prevented the proximal migration of the first metacarpal in all but one patient. No patients required revision arthroplasty following LRSA. CONCLUSIONS: This study demonstrates the consistent short, intermediate, and long-term clinical, functional, and radiographic outcomes following a trapeziectomy with FCR suspension arthroplasty.

Component sizing in total knee arthroplasty: patient-specific guides vs. computer-assisted navigation.

INTRODUCTION: Patient-specific guides (PSG) and computer-assisted navigation (CAN) are technologies that have been developed to improve the accuracy and reproducibility of total knee arthroplasty (TKA). The purpose of this study is to compare the methodology by which a PSG system and an intraoperative navigation system (CAN) perform an anatomical registration and correctly predict femoral component size in TKA. METHODS: One hundred and eleven PSG TKA were performed, 30 of which were concurrently evaluated with CAN. PSG-predicted and CAN-predicted femoral component size were compared with the actual component selection. The process by which PSG and CAN determines component sizing was evaluated. RESULTS: The PSG system was both more accurate and more precise than the CAN navigation system in predicting femoral component size in TKA. CONCLUSION: In this study, the surgeon's final component selection was more likely to be in accordance with the PSG rather than the CAN sizing algorithm. This study suggests that intraoperative surface registration may not be as accurate as preoperative three-dimensional magnetic resonance imaging reconstructions for establishing optimal femoral component sizing.

Radiographic and navigation measurements of TKA limb alignment do not correlate.

UNLABELLED: Precise pre- and postoperative anatomic measurements are necessary to plan, perform, and evaluate total knee arthroplasty (TKA). We evaluated the relationship between radiographic and navigation alignment measurements, identified sources of error in radiographic and navigated alignment assessment, and determined the differences between desired and clinically accepted alignment. Fifty-eight computer-assisted TKAs were performed and limb alignment measurements were recorded both pre- and postoperatively with standard radiographs and with an intraoperative navigation system. Intraoperative navigation produced consistent navigation-generated alignment results that were within 1 degrees of the desired alignment. The difference between preoperative radiographic and navigation measurements varied by as much as 12 degrees and the difference between postoperative radiographic and navigation measurements varied by as much as 8 degrees. This discrepancy depended on the degree of limb deformity. Postoperative radiographic measurements have inherent limitations. Navigation can generate precise, accurate, and reproducible alignment measurements. This technology can function as an effective tool for assessing pre- and postoperative limb alignment and relating intraoperative alignment measurements to clinical and functional outcomes. LEVEL OF EVIDENCE: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Columbus primary total knee replacement: a 2- to 4-year followup of the use of intraoperative navigation-derived data to predict pre and postoperative function.

The purpose of this study was to examine the clinical outcomes associated with the Columbus primary total knee replacement (B. Braun Aesculap, Tuttlingen, Germany), correlate these outcomes with variables measured intraoperatively with the OrthoPilot navigation system (B. Braun Aesculap), and explore the full potential of automating the process of intraoperative data collection. Clinical and functional outcomes at 2.5 years were similar to results reported in previous studies. Correlations were seen between initial mechanical axis deformity and postoperative range of motion as well as between final mechanical axis alignment and the presence of flexion contractures at later followup. It is now possible to potentially stratify particular segments of patients and develop specific intraoperative alignment targets that are most likely to yield positive clinical and functional outcomes.