Deana Mercer

Postsurgical Chondrolysis of the Shoulder

There are multiple reports in the literature of chondrolysis following arthroscopic shoulder surgery. Although the etiology of these cases is not known for certain, there has been speculation that radiofrequency devices, young patient age, instability surgery, intra-articular pain pumps, and type of anesthetic may be precipitating factors. This article describes a case of a 37-year-old law enforcement officer who injured both shoulders and ultimately underwent nearly identical bilateral procedures: arthroscopic superior labrum anteroposterior (SLAP) repair, Bankart repair, capsulorrhaphy, acromioplasty, and distal clavicle excision. Intra-articular pain catheters were placed following both procedures, but the right-sided catheter never functioned properly, as evidenced by continuous leakage outside of her body until it was removed. Subsequently she had an arthroscopic lysis of adhesions done for residual stiffness, in which the left humeral head and glenoid cavity were noted to be completely devoid of articular cartilage. Over the ensuing months, multiple cortisone injections, 5 viscosupplementation injections, physical therapy, and narcotics all failed to relieve her left shoulder pain. Radiographs showed significant left glenohumeral joint space narrowing and a normal-appearing joint space on the right. Our impression was postsurgical chondrolysis of the left shoulder. The patient has recently undergone humeral hemiarthroplasty with nonprosthetic glenoid arthroplasty. This case differs from others reported in the literature in that nearly identical bilateral procedures were performed by the same surgeon, yet chondrolysis only developed on the side that had a functioning postoperative pain catheter.

Comparison of Patients Undergoing Primary Shoulder Arthroplasty Before and After the Age of Fifty

BACKGROUND The reported outcomes of shoulder arthroplasty in patients under the age of fifty years are worse than those in patients over fifty. While there are several possible explanations for this finding, we explored the possibility that patients who had a primary shoulder arthroplasty when they were under fifty years of age differed from those who had the procedure when they were over fifty with respect to their pre-arthroplasty self-assessed comfort and function, sex distribution, and specific type of arthritis. METHODS The study group consisted of patients with glenohumeral arthritis who were treated with a primary shoulder arthroplasty by the same surgeon between 1990 and 2008. For each decade of age, the sex distribution, the pre-arthroplasty self-assessed shoulder comfort and function, and the prevalence of twelve different diagnoses were documented. We reviewed the series for three potential causes of worse outcomes in patients under fifty years of age as compared with those over fifty years of age: (1) a higher percentage of women, (2) a lower score for pre-arthroplasty self-assessed comfort and function, and (3) more complex pathological conditions. RESULTS Patients under the age of fifty years were not more likely than those over fifty to be female or to have a lower pre-arthroplasty self-assessed comfort and function score, but they did have more complex pathological conditions, such as capsulorrhaphy arthropathy, rheumatoid arthritis, and posttraumatic arthritis. Only 21% of the younger patients had primary degenerative joint disease, whereas 66% of the older patients had that diagnosis. This difference was significant (p < 0.000000001). CONCLUSIONS Surgeons performing shoulder arthroplasty in individuals under the age of fifty should be prepared to encounter pathological conditions such as capsulorrhaphy arthropathy, rheumatoid arthritis, and posttraumatic arthritis rather than primary osteoarthritis, which is more common in individuals older than fifty. The pathoanatomy in these younger patients may complicate the surgery, the rehabilitation, and the outcome of the shoulder arthroplasty.

Shoulder hemiarthroplasty with concentric glenoid reaming in patients 55 years old or less.

BACKGROUND Glenohumeral arthritis in younger individuals is challenging because of the complex pathology, need for extended durability, and high expectations of the patients. Humeral hemiarthroplasty combined with concentric glenoid reaming is a surgical option for the management of glenohumeral arthritis that avoids the risks of glenoid component failure and avoids the challenges of tissue interposition. The results of this procedure in young patients have not been previously reported. METHODS Sixty-five shoulders in patients who were 55 years old or less at the time of surgery underwent humeral hemiarthroplasty combined with concentric glenoid reaming and were followed for a minimum of 2 years or until the time of revision surgery. Patient self-assessments of shoulder comfort and function were compared before and after surgery. For 22 of these shoulders, standardized radiographs were available for follow-up evaluation. RESULTS Nine shoulders required revision surgery. These shoulders had 3 ± 3 prior surgeries, in comparison to 1 ± 1 prior surgeries for the unrevised group. For the 56 unrevised shoulders, the number of Simple Shoulder Test functions that could be performed improved from a mean of 4.1 before surgery to a mean of 9.5 at an average follow-up of 43 months (range, 24-85) (P < .001). For the 22 shoulders with radiographic follow-up, medial glenoid erosion averaged 1.1 mm (range, 0.0-6.3 mm) at an average of 44 months after the procedure. CONCLUSION In selected patients 55 years or younger with glenohumeral arthritis, this procedure can provide significant improvement in self-assessed shoulder comfort and function.

Trends in the orthopedic job market and the importance of fellowship subspecialty training.

Previous studies have examined possible incentives for pursuing orthopedic fellowship training, but we are unaware of previously published studies reporting the trends in the orthopedic job market since the acceptance of certain criteria for fellowship programs by the Accreditation Council for Graduate Medical Education (ACGME) in 1985. We hypothesized that, since the initiation of accredited postresidency fellowship programs, job opportunities for fellowship-trained orthopedic surgeons have increased and job opportunities for nonfellowship-trained orthopedic surgeons have decreased. We reviewed the job advertisements printed in the Journal of Bone and Joint Surgery, American Volume, for the years 1984, 1994, 2004, and 2009. We categorized the job opportunities as available for either a general (nonfellowship-trained) orthopedic surgeon or a fellowship-trained orthopedic surgeon. Based on the advertisements posted in the Journal of Bone and Joint Surgery, American Volume, a trend exists in the orthopedic job market toward seeking fellowship-trained orthopedic surgeons. In the years 1984, 1994, 2004, and 2009, the percentage of job opportunities seeking fellowship-trained orthopedic surgeons was 16.7% (95% confidence interval [CI], 13.1%-20.3%), 40.6% (95% CI, 38.1%-43.1%), 52.2% (95% CI, 48.5%-55.9%), and 68.2% (95% CI, 65.0%-71.4%), respectively. These differences were statistically significant (analysis of variance, P<.05). Fellowship training is thus a worthwhile endeavor.

A quantitative method for determining medial migration of the humeral head after shoulder arthroplasty: preliminary results in assessing glenoid wear at a minimum of two years after hemiarthroplasty with concentric glenoid reaming

HYPOTHESIS Glenoid erosion and medial migration of the humeral head prosthesis have been observed after most types of shoulder arthroplasty. A method of measuring the change in humeral head position with time after shoulder prosthetic arthroplasty was applied it to 14 shoulders that underwent humeral hemiarthroplasty with concentric glenoid reaming. We hypothesized that the measurement technique would be reproducible and that the rate of wear would be small in the series of shoulders studied. MATERIALS AND METHODS Standardized anteroposterior and axillary radiographs were obtained after surgery. Two examiners measured the position of the humeral head center in relation to scapular reference coordinates for the anteroposterior and axillary projections and plotted these values against time after surgery. The change in position was characterized as the slope of this plot. Shoulders were included if there were at least 3 sets of postoperative films, the last being at least 2 years after surgery. RESULTS The slopes measured by the 2 examiners agreed within 0.5 mm/y for the anteroposterior and the axillary projections. For the series of shoulder arthroplasties, the rate of movement of the head center toward the scapula was less than 0.4 mm/y for either examiner in either projection. DISCUSSION Medial migration is a concern after any type of shoulder arthroplasty, whether a hemiarthroplasty, a biological interpositional arthroplasty, or a total shoulder arthroplasty. Quantifying the rate of medial migration over time after shoulder arthroplasty is an important element of clinical follow-up. CONCLUSIONS This is an inexpensive, practical, and reproducible method that can be used to determine the rate of medial migration of the humeral head on plain radiographs after shoulder arthroplasty. The average rate of medial migration in the shoulders in this study was small.

A method for documenting the change in center of rotation with reverse total shoulder arthroplasty and its application to a consecutive series of 68 shoulders having reconstruction with one of two different reverse prostheses.

BACKGROUND Reverse shoulder arthroplasty changes the center of rotation (COR) of the glenohumeral joint and in doing so affects the resting tension in the deltoid and residual cuff muscles, as well as their respective moment arms. The purpose of this study was to assess the change in COR from the preoperative to postoperative state in a group of patients undergoing reverse shoulder arthroplasty. MATERIALS AND METHODS The position of the COR in relation to a scapular coordinate system was determined for the anteroposterior and axillary radiographs before and after reverse total shoulder arthroplasty for 68 shoulders (63 patients) receiving either a Delta prosthesis or an Encore Reverse Shoulder Prosthesis. RESULTS Preoperatively, the COR was superiorly displaced a mean of 9 ± 7 mm from the origin of the coordinate system. For all shoulders, the postoperative COR was inferiorly displaced by 12 mm to a position 3 ± 3 mm below the coordinate origin (P < .001) and medially displaced by 27 ± 4 mm from the coordinate origin (P < .001) in the anteroposterior projection. For the shoulders receiving the Delta prosthesis, the COR was inferiorly displaced by 2 ± 3 mm from the coordinate origin, whereas it was inferiorly displaced by 7 ± 3 mm with the Encore prosthesis (P < .001). The COR was medially displaced by 28 ± 4 mm with the Delta prosthesis and by 19 ± 3 mm with the Encore prosthesis (P < .001). CONCLUSIONS The position of the COR relative to the scapula is significantly altered by reverse shoulder arthroplasty and is significantly different for 2 different implant designs.

Hardware removal after fracture fixation procedures in the femur.

Background: The purpose of this study was to conduct an examination of internal fixation of femoral fractures in a large national database. The study aims were to determine the percentage of fixation procedures that result in hardware removal in a single year and to assess differences in the likelihood for hardware removal procedures using patient characteristics. Methods: The 2007 Nationwide Inpatient Sample was used to quantify all patients who received an open reduction and internal fixation procedure for a fracture of the femur and all patients with a removal of implanted devices from the femur. The differences in patient characteristics between both groups were assessed using statistical methods. Results: Internal fixation of the femur was reported in 30,943 patients. Hardware removals were reported in 4,886 patients. The removal rate for the year was estimated to be 15.8%. Treatment failure was most often because of mechanical complications (18.7%), osteoarthritis (14.3%), nonunion (13.9%), refracture (10.9%), and other implant-oriented complications (10.1%). Males and younger patients composed a significantly higher percentage of removal procedures than fixation procedures (p < 0.0001 for both). Removal rates were lower in Self-Pay and Medicare patients, while the opposite was true for Medicaid and private insurance/HMO patients (p < 0.0001). Conclusion: The results of this study suggest that gender, age, and insurance status may influence the likelihood of an implant removal procedure. Given that removal was more likely in males and younger patients, and most often because of mechanical and implant-oriented complications, patient activity and weight bearing are likely leading factors in implant removal.

Experimental and probabilistic analysis of distal femoral periprosthetic fracture: a comparison of locking plate and intramedullary nail fixation. Part A: experimental investigation

The following is Part B of a two-part study. Part A evaluated, biomechanically, intramedullary (IM) nails versus locking plates for fixation of an extra-articular, metaphyseal wedge fracture in synthetic osteoporotic bone. Part B of this study introduces deterministic finite element (FE) models of each construct type in synthetic osteoporotic bone and investigates the probability of periprosthetic fracture of the locking plate compared with the retrograde IM nail using Monte Carlo simulation. Deterministic FE models of the fractured femur implanted with IM nail and locking plate, respectively, were developed and validated using experimental data presented in Part A of this study. The models were validated by comparing the load–displacement curve of the experimental data with the load–displacement curve of the FE simulation with a root-mean square error of less than 3 mm. The validated FE models were then modified by defining the cortical and cancellous bone modulus of elasticity as uncertain variables that could be assumed to vary randomly. Monte Carlo simulation was used to evaluate the probability of fracture (POF) of each fixation. The POF represents the cumulative probability that the predicted shear stresses in the cortical bone will exceed the expected shear strength of the cortical bone. This investigation provides information regarding the significance of post-operative damage accumulation on the POF of the implanted bones when the two fixations are used. The probabilistic analysis found the locking plate fixation to have a higher POF than the IM nail fixation under the applied loading conditions (locking plate 21.8% versus IM nail 0.019%).

Opening Wedge Trapezial Osteotomy as Possible Treatment for Early Trapeziometacarpal Osteoarthritis: A Biomechanical Investigation of Radial Subluxation, Contact Area, and Contact Pressure

PURPOSE Radial subluxation and cartilage thinning have been associated with initiation and accelerated development of osteoarthritis of the trapeziometacarpal joint. Few investigators have reported on the benefits of opening wedge trapezial osteotomy for altering the contact mechanics of the trapeziometacarpal joint as a possible deterrent to the initiation or progression of osteoarthritis. We used cadaveric specimens to determine whether opening wedge osteotomy of the trapezium was successful in reducing radial subluxation of the metacarpal base and to quantify the contact area and pressure on the trapezial surface during simulated lateral pinch. METHODS We used 8 fresh-frozen specimens in this study. The flexor pollicis longus, abductor pollicis longus, adductor pollicis, abductor pollicis brevis, and flexor pollicis brevis/opponens pollicis tendons were each loaded to simulate the thumb in lateral pinch position. We measured radial subluxation from anteroposterior radiographs before and after placement of a 15° wedge. We used real-time sensors to analyze contact pressure and contact area distribution on the trapezium. RESULTS Center of force in the normal joint under lateral pinch loading was primarily located in the dorsal region of the trapezium. After wedge placement, contact pressure increased in the ulnar-dorsal region by 76%. Mean contact area increased in the ulnar-dorsal region from 0.05 to 0.07 cm(2), and in the ulnar-volar region from 0.003 to 0.024 cm(2). The average reduction in joint subluxation was 64%. CONCLUSIONS The 15° opening wedge osteotomy of the trapezium reduced radial subluxation of the metacarpal on the trapezium and increased contact pressure and contact area away from the diseased compartments of the trapezial surface. Trapezial osteotomy addresses the 2 preeminent theories about the initiation and progression of osteoarthritis. CLINICAL RELEVANCE By reducing radial subluxation and altering contact pressure and contact area, trapezial osteotomy may prove an alternative to first metacarpal extension osteotomy or ligament reconstruction in early stages of degenerative arthritis of the trapeziometacarpal joint.

Late reconstruction of chronic distal biceps tendon ruptures using fascia lata autograft and suture anchor fixation.

Distal biceps tendon ruptures are a rare injury, and surgical reconstruction is typically recommended for chronic ruptures. There is no consensus regarding the most appropriate reconstruction technique. We present our experience with reconstruction of chronic distal biceps tendon ruptures with fascia lata autograft, secured to the bicipital tuberosity with suture anchors. A single anterior incision is used for all patients. Tension is set with the elbow in 50 degrees of flexion. Ninety-two percent of our patients reported improvement in elbow flexion and supination and were pleased with the surgery. Range of motion and isokinetic flexion and supination strength after this procedure was comparable with other distal biceps tendon reconstruction options using tendon grafts and suture anchor fixation from a single anterior approach. Furthermore, common complications associated with distal biceps tendon repair and reconstruction can be avoided with this technique. We therefore feel that this technique is a viable surgical treatment alternative with good subjective and objective outcomes. Level of Evidence: Level IV.