Radiographic assessment of uncemented humeral components in total shoulder arthroplasty

Seventy-two total shoulder arthroplasties performed using Neer II press-fit humeral components and followed for an average of 4.1 years (range, 2-7.8 years) were analyzed radiographically. A humeral component was considered radiographically at risk for clinical loosening when a radiolucent line > or =2 mm in width was present in > or =3 zones or tilt or subsidence was identified on sequential radiographs by 2 of 3 or 3 of 3 independent observers. Forty components (55.6%) were judged to be at risk. There were no identifiable characteristics associated with the development of an at-risk humeral component except longer average follow-up of the at-risk group (4.7 years vs 3.3 years, P =.001). Humeral components at risk had a higher rate of endosteal erosion (P =.04) and greater number of zones with sclerosis. Radiographic changes around Neer II uncemented humeral components are common. Data from this study can be used as 1 benchmark to compare with alternate methods of humeral component fixation.     

Radiographic assessment in total knee arthroplasty

Sixty-five total knee arthroplasties were evaluated by the Knee Society Radiological Evaluation System which was developed to encourage uniform reporting of the results of total knee arthroplasty. All patients were examined by three independent experienced radiologists 8.9 years after surgery (range, 3-16 years) to analyze the interobserver variability. For measurement of angles, high interobserver correlation was calculated for the prosthetic component angles and the femorotibial shaft angle. The comparison of the means indicated no significant differences except for the femorotibial shaft angle. For measurement of radiolucent lines, interobserver correlation was low for all components. The differences of the means were significantly different for all components. The results of interobserver variability of the patellar evaluation revealed high interobserver correlation for the patellar angle and for patellar subluxation and dislocation evaluation. For assessment of patellar mediolateral and superoinferior displacement, a low interobserver correlation was found. For radiographic assessment of total knee arthroplasty, the measurement of angles, including alpha, beta, femorotibial shaft angle, sagittal femoral and tibial component angle, patellar angle, and patellar subluxation and dislocation evaluation are recommended. The method of assessing radiolucent lines should be reconsidered.     

Radiographic assessment of cemented humeral components in shoulder arthroplasty

Forty-three shoulder arthroplasties performed with the use of cemented Neer II humeral components and followed radiographically for a mean of 6.6 years (range, 2-20 years) were analyzed. A humeral component was considered radiographically "at risk" for clinical loosening when a radiolucent line 2 mm or greater in width was present in 3 or more zones or tilt or subsidence was identified on sequential radiographs by 2 or 3 of the 3 independent observers. None of the components was considered to have tilted or subsided. Radiolucent lines of any size were present in 16 shoulders and were wider than 2 mm in 9 shoulders. They were limited to 1 zone in 8 shoulders and to 2 zones in 7 shoulders. Only 1 component (2%) with a 2-mm radiolucent line in 3 zones was judged to be "at risk." The incidence, extent, and thickness of humeral radiolucent lines were significantly higher in total arthroplasties than in hemiarthroplasties (P <.05). Clinically important changes around cemented Neer II humeral components are uncommon. Humeral radiolucent lines develop more frequently in the presence of a glenoid component. Data from this study can be used as one benchmark to compare with alternate methods of humeral component fixation.     

Prospective assessment of osteoporosis in total shoulder arthroplasty

HypothesisThe risks of shoulder arthroplasty in those with osteopenia and osteoporosis are not fully understood. The purpose of this study was to prospectively evaluate intraoperative complications in those undergoing shoulder arthroplasty with low bone mineral density (BMD).MethodsWe prospectively enrolled consecutive patients undergoing shoulder arthroplasty with a preoperative computed tomography (CT) scan from January to July 2021. Exclusion criteria included age <50 years, revision surgery, fracture, diagnosis of inflammatory arthropathy, or active infection. An intraoperative survey assessing bone quality and complications was collected. A blinded reviewer then measured bone quality based on preoperative CT scan using a previously validated method. Subjects were then divided between normal and low BMD groups with low BMD including both osteopenia and osteoporosis.ResultsWe enrolled 75 consecutive patients who met all inclusion criteria. Nine patients were excluded due to incomplete imaging leaving a final cohort of 66 patients. The average age was 69.2 years (50.4-88.5 years), with 41 males (62.1%) and 25 females (37.9%). There were 33 anatomic total shoulder arthroplasties and 33 reverse shoulder arthroplasties. Surgeons were very accurate in identifying normal bone intraoperatively (95.5% correct) but less accurate in identifying poor bone quality (45.5% correct). Surgeons reported making changes to their plan or technique in 8 cases (12%), with 7 (87.5%) of these changes occurring in those with poor bone quality. The lesser tuberosity was damaged with posterior retraction in 16 cases (24.2%), with 13 (81.3%) of those being in patients with poor bone quality. There was 1 intraoperative glenoid rim fracture, which occurred in a patient with low bone density.ConclusionThe prevalence of osteoporosis in the population undergoing shoulder arthroplasty is high. Performing shoulder arthroplasty on those with poor bone quality presents multiple challenges, which are underappreciated. Being able to better predict bone quality based on preoperative CT imaging can alert the surgeon to potential intraoperative complications.     

Radiographic comparison of two glenoid preparation techniques in total shoulder arthroplasty

We compared the prevalence of periglenoid radiolucencies between two glenoid component preparation techniques used in total shoulder arthroplasties. Seventy-two consecutive patients with primary osteoarthritis had total shoulder arthroplasties using one prosthetic system with flat-back keeled polyethylene glenoid components. Thirty-seven shoulders had glenoid implants that were cemented after standard curettage preparation of the keel slot. Thirty-five shoulders had glenoid implants that were cemented after using bone compaction to prepare the keel slot. The immediate postoperative and 2-year postoperative radiographs were examined to evaluate the presence and progression of periglenoid radiolucencies. The curettage group had a higher rate (38%) of keel radiolucencies than the compaction group (11%) seen on the immediate postoperative radiographs. Both groups had progression of periglenoid radiolucencies with time. Progression of the radiolucent lines was worse in the curettage group 2 years after arthroplasty. Preparation of the glenoid component keel slot with the bone compaction technique seems to achieve better fixation of flat-back keeled polyethylene glenoid components in total shoulder arthroplasties.     

Radiographic assessment of knee alignment after total knee arthroplasty

Standard anteroposterior standing radiographs (14 X 17-inch cassettes) and full-limb radiographs (51-inch) from a randomized group of 50 patients undergoing total knee arthroplasty between January 1985 and June 1986 were analyzed. The mean tibiofemoral angle on short films was 5.8 degrees valgus, compared with 7.2 degrees valgus on full-limb films. This 1.4 degrees discrepancy had a standard deviation of 2.2 degrees, emphasizing the measurement variability in any individual case. The distance from the knee center to the mechanical axis related linearly to the tibiofemoral angle. Twenty-six percent (13 of 50) of knee arthroplasties failed to achieve satisfactory postoperative alignment of 4-10 degrees valgus in this study.     

Radiographic comparison of flat-back and convex-back glenoid components in total shoulder arthroplasty

The purpose of this study was to compare the radiographic results of 2 different glenoid component designs. This series consisted of 66 shoulder arthroplasties with primary osteoarthritis divided into 2 groups based on glenoid component type. One group comprised shoulders receiving cemented flat-back polyethylene glenoid implants. The other group comprised shoulders receiving cemented convex-back polyethylene glenoid implants. Immediate postoperative and 2-year postoperative radiographs were evaluated for the presence and progression of periglenoid radiolucencies, and the 2 groups were compared. Radiolucent line scores were calculated and compared for each group. The keeled, convex-back glenoid component was radiographically better than the keeled, flat-back glenoid component.     

Bilateral anatomic total shoulder arthroplasty versus reverse shoulder arthroplasty

The results of anatomic total shoulder arthroplasty and reverse shoulder arthroplasty have previously been reported separately. Although the indications differ, scenarios exist in which a patient may have a total shoulder arthroplasty on 1 shoulder and a reverse shoulder arthroplasty on the contralateral shoulder.Between 1992 and 2009, twelve patients underwent bilateral sequential primary shoulder arthroplasty with a total shoulder arthroplasty on 1 side and reverse shoulder arthroplasty on the contralateral side. Constant score, American Shoulder and Elbow Surgeons (ASES) score, subjective shoulder value, and patient satisfaction were obtained a minimum 1 year postoperatively. Mean postoperative Constant score was 77 after total shoulder arthroplasty and 73 after reverse shoulder arthroplasty (P<.2488). Mean postoperative active forward flexion was similar after total shoulder arthroplasty compared with reverse shoulder arthroplasty (P=.8910). Greater external rotation at the side (43° vs 12°; P<.0001) and internal rotation (T8 vs L1; P<.0001) were observed after total shoulder arthroplasty. Mean ASES score was 89.6 after total shoulder arthroplasty compared with 82.4 after reverse shoulder arthroplasty (P=.0125). Patient satisfaction was 92% for both prostheses, and mean subjective shoulder value was similar (85.4% vs 82.5%; P=.6333).Bilateral shoulder arthroplasty performed with a total shoulder arthroplasty and reverse shoulder arthroplasty on opposite shoulders can provide good functional outcome and high patient satisfaction. Although range of motion is better following total shoulder arthroplasty, no difference was observed in final Constant score or subjective patient assessment.     

Radiographic methods for the assessment of polyethylene wear after total hip arthroplasty

All wear-measurement techniques assess femoral head penetration and therefore cannot distinguish between true polyethylene wear and bedding-in. Multiple wear measurements that are made at different time-intervals after bedding-in has occurred are required to determine the true wear rate. Computer-assisted edge-detection techniques offer improved accuracy and precision compared with manual techniques and appear to be ideally suited for the retrospective and prospective examination of large groups of patients with intermediate to long-term radiographic follow-up (more than five years). While radiostereometric analysis offers improved accuracy and precision compared with computer-assisted edge-detection techniques, widescale clinical application is limited because of its relative expense, the required expertise, and the fact that it can only be used in a prospective fashion.