BackgroundShort uncemented stems have recently been proposed as an alternative to classic long stems for shoulder arthroplasty. The early results are promising, but bony adaptations of the proximal humerus have been reported. The aim of this study was to quantify these phenomena using the Ascend Flex stem and to determine the risk factors.Materials and methodsIn a retrospective, single-center study, 183 shoulder arthroplasties were evaluated at 2-year follow-up. All patients underwent clinical evaluations preoperatively and at last follow-up. Radiographs were obtained preoperatively, postoperatively, and at last follow-up. Four types of bony adaptations were analyzed: medial cortical narrowing (MCN), medial metaphysis thinning (MMT), lateral metaphysis thinning (LMT), and under-the-baseplate osteolysis. The risk factors were analyzed in a multivariate model.ResultsMCN was found in 72.6% of cases and was severe (>50%) in 4.4%. MMT was found in 46.4% of cases and was severe in 3.3%. LMT was found in 9.8% of cases and was severe in 2.8%. The risk factors for MCN were the distal filling ratio, osteoporosis, and female sex, whereas MMT and LMT were only influenced by stem axis deviation. Under-the-baseplate osteolysis was found in 34.4% of cases. No influence of bony adaptations on the clinical outcomes was observed. We found no complications related to the stem or to stem loosening.ConclusionThe radiographic evolution was satisfactory at mid-term follow-up. Bony adaptations seemed to be limited phenomena, without any observed consequence. Avoiding excessive filling and axis deviation may limit these phenomena.
Introduction: As the revision number of shoulder arthroplasties increases, we focused on the difficulties of extracting or converting the humeral stem. The purpose of this multicentric study was to assess the outcomes and the radiographic results of a new, short, and convertible humeral stem (Aequalis Ascend TM Flex, Tornier SAS-Wright Medical Inc Õ , Bloomington, MN, USA), which could settle these complex revision problems. Methods: Sixty-six primary shoulder replacements were enrolled with an average follow-up of 25.6 months (24-30.8 months). There were 24 reversed shoulder arthroplasty (RSA) and 42 anatomical shoulder arthroplasty. The functional outcomes were evaluated with the Constant-Murley score (CS) and the active range of motion. Humeral stems were radiologically analyzed at the last follow-up with special care to mechanical complications and bone resorption. Results: The average CS improved from 30 preoperatively to 74 postoperatively (P <.0001) for anatomical shoulder replacements and from 21 to 63 (P <.0001) for RSA. The active anterior elevation and external rotation improved from 97 and 6 to 163 and 46 , respectively, for anatomical prosthesis (P <.0001) and from 79 and 10 to 139 and 28 , respectively, for RSA (P <.0001). No mechanical complication or loosening was reported. The comparison between postoperative and last followup X-rays showed a tendency to medial cortical bone thinning in some cases without any clinical relevance. Conclusion: Two years follow-up of this short stem showed promising clinical and radiographic results without implantrelated complication. Further X-rays study would be necessary.
Background
Due to it being tangential to the distal femoral axis, the anteromedial portal presents significant risk of causing iatrogenic damage, and of producing tunnels that are too short for optimal osseointegration. Flexible reamers were developed to eliminate the need for knee hyperflexion and offer better-controlled orientation of the femoral tunnel. We aimed to compare the anteversion and length of femoral tunnels drilled using flexible reamers to those drilled using rigid reamers.
Methods
Between May 2012 and December 2013, all patients receiving ACL reconstruction performed by one surgeon were operated on using either a rigid or a flexible reamer from the same supplier (Versi-Tomic® system, Stryker, Kalamazoo, Michigan). The height of each patient was recorded, and the length and anteversion of the femoral tunnels were measured intra-operatively and on true lateral radiographs, respectively.
Results
Thirty-seven patients underwent operations using the rigid instrumentation, and 43 using the flexible instrumentation. There was no statistically significant difference between the two groups in either sex or height (
p
= n.s.). The patients operated on using the rigid instrumentation had tunnels anteverted by 18.6° ± 6° and 33.6 ± 2.9 mm long. Those operated on using the flexible instrumentation had tunnels anteverted by 40° ± 2° and 41.1 ± 3.57 mm long. Both anteversion and tunnel length were significantly greater for tunnels drilled using the flexible instrumentation (
p
< 0.001).
Conclusions
This study demonstrated that flexible reamers produce significantly more anteverted and longer femoral tunnels during ACL reconstruction than rigid reamers. Clinical studies remain necessary to assess the outcomes of ACL reconstruction using flexible reamers.
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