Anatomic fit of precontoured extra-articular distal humeral locking plates: a cadaveric study

Background: Extra-articular distal humerus locking plates (EADHPs) are precontoured anatomical plates widely used to repair distal humeral extra-articular diaphyseal fractures. However, EADHPs frequently cause distal protrusion and resulting skin discomfort. The purpose of this study was to predict the occurrence of anatomic fit mismatch. We hypothesized that the smaller the humerus size, the greater the anatomic fit mismatch with EADHP. Methods: Twenty humeri were analyzed in this study. Humeral length and distal humeral width were used as parameters of humeral size. Plate protrusion was measured between the EADHP distal tip and the distal humerus. We set the level of unacceptable EADHP anatomic fit mismatch as ≥10 mm plate protrusion. Results: A significant negative linear correlation was also confirmed between humeral size and plate protrusion, with a coefficient of determination of 0.477 for humeral length and 0.814 for distal humeral width. The cutoff value of humeral length to avoid ≥10 mm plate protrusion was 293.6 mm (sensitivity, 88.9%; specificity, 81.8%) and for distal humeral width was 60.5 mm (sensitivity, 100%; specificity, 81.8%). Conclusions: Anatomic fit mismatch in distal humeral fractures after EADHP fixation has a negative linear correlation with humeral length and distal humeral width. For patients with a distal humeral width <60.5 mm, ≥10 mm plate protrusion will occur when an EADHP is used, and an alternative implant or approach should be considered.ope

Atypical femoral fracture combined with osteonecrosis of jaw during osteoporosis treatment with bisphosphonate.

Bisphosphonate, a potent anti-resorptive agent, is generally accepted as a safe, effective, well tolerated treatment for postmenopausal osteoporosis. Atypical femoral fracture (AFF) and bisphosphonate related osteonecrosis of jaw (BRONJ) are the increasing morbidities in patients treated with long term bisphosphonate. Pathogenic mechanisms of AFF and BRONJ are not fully identified and not identical. We report a case of BRONJ followed by AFF and its nonunion in a 67-year-old woman patient receiving an oral bisphosphonate during 7 years for the treatment of osteoporosis.ope

The biomechanical effect of fibular strut grafts on humeral surgical neck fractures with lateral wall comminution

No studies have evaluated the effect of fibular strut augmentation on the stability of locking plate fixation for osteoporotic proximal humeral fractures with lateral wall comminution. The purpose of this study was to evaluate the stability of locking plate fixation with a fibular strut graft compared with locking plate alone in an osteoporotic two-part surgical neck fracture model with lateral cortex comminution. Ten paired fresh-frozen cadaveric humeri were randomly allocated into two groups, either the locking plate alone (LP group) or locking plate with fibular strut graft augmentation (LPFSG group), with an equal number of right and left osteoporotic surgical neck fractures with lateral wall comminution of the greater tuberosity. Varus, internal/external torsion, and axial compression stiffness as well as single load to failure were measured in plate-bone constructs, and the LPFSG group showed significantly greater values in all metrics. In conclusion, this biomechanical study shows that fibular strut augmentation significantly enhances varus stiffness, internal torsion stiffness, external torsion stiffness, and maximum failure load of a construct compared to locking plate fixation alone in proximal humeral fractures with lateral wall comminution. © 2023, The Author(s).ope

원위 상완골 관절 외 골간부 골절에서 PHILOS 금속판의 변형 적용

Introduction: The upside-down use of a proximal humerus internal locking system (PHILOS) plate is suggested as an alternative option for distal extra-articular diaphyseal humeral fracture fixation without biomechanical evidence, while extra-articular distal humerus locking plate (EADHP) is widely used. The purpose of this study was to compare the biomechanical performance between two different fixation methods: a modified use of the PHILOS plate on the anterior cortex versus conventional use of an EADHP on the posterior cortex. Methods: Twelve pairs of fresh-frozen cadaveric humeri were used and 7mm gap osteotomy was performed at 50mm proximal to the lateral epicondyle to simulate a fracture model. Single load to failure was measured after five stiffness tests of the plate-bone constructs in anterior/posterior bending stiffness, internal/external torsional stiffness, and axial compressional stiffness. Results: There were no significant differences in metrics between the two groups, except for the load to failure in posterior bending, which was significantly higher for PHILOS (1589.3 ± 234.5N) compared to EADHP (1430.1 ± 188.6 N) (p<0.023). Conclusion: The modified use of PHILOS plate showed comparable biomechanical performance compared to the conventional EADHP. The new fixation method offers the potential clinical advantages, considering the patient’s position and surgical approach at the time of surgery as well as postoperative soft tissue irritation. Therefore, this could be an option for distal humeral extra-articular diaphyseal fracture fixation when the use of EADHP is not suitable or preferred. 연구 배경 및 목적: 근위 상완골용 잠김금속판을 원위 상완골의 관절 외 골간부 골절에서 역적용 하는 것이 고식적으로 사용되는 잠김 금속판을 이용해 고정하는 것에 대안적인 치료법이 될 수 있다고 제시되고 있으나 이에 대한 생역학적 근거가 부족하다. 본 연구의 목적은 접근법이 다른 두 가지의 잠김 금속판의 생역학적 성능을 비교하는 것으로 원위 상완골 전방에 변형 적용하는 근위 상완골 잠김 금속판군과, 고식적 후방 고정 잠김금속판군을 비교 분석하였다. 연구 재료 및 방법: 12구의 카데바 상완골 좌, 우 대응표본을 대상으로 하였으며 외상과 근위부 50mm 위치에 7mm 골간격 골절 모형을 생성하였다. 전/후방 굽힘 강성, 내/외회전 비틀림 강성 및 축 압축 강성을 측정한 후 단회 항복 강도을 측정 하였다. 연구 결과: 단회 항복 강도(뉴턴)는 변형 적용된 근위 상완골 잠김 금속판군 (1589.3 ± 234.0) 에서 고식적 잠김 금속판군 (1430.0 ± 188.6) 에 비해 통계적으로 유의미한 차이를 보였고 (p < 0.023), 그 이외의 측정값들에서는 두 군간 유의미한 차이를 보지 않았다. 결론: 원위 상완골의 관절 외 골간부 골절모형에서 근위 상관골 잠김 금속판 변형 적용군은 고식적 잠김 금속판 고정군과 비교할만한 생역학적 성능을 보였다. 새로운 잠김 금속판 변형 적용법은 전방 접근을 통해 양와위로 수술이 가능하며, 수술 후 내고정물 자극이 적다는 임상적 장점이 있다. 따라서 상완골 원위부 관절외 관절외 골간부 골절에서 고식적인 후방 접근 잠김 금속판의 사용이 적합하지 않거나 선호되지 않을 경우에, 근위 상완골 잠김 금속판 변형 적용하는 수술방법이 대안이 될 수 있다.open박

Development of PDR and PDRO for mm-wave Band

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Assessment of Bosworth-type fracture by external oblique radiographs

Introduction : Bosworth described an unusual fracture dislocation of the ankle with fixed posterior fracture dislocation of the fibula. This ankle fracture variant is often not recognized in initial radiographs and requires a computed tomographic scan for verification. It is usually not reducible by the closed method, and repeated trials induce more damage. The purpose of this study was to verify the usefulness of simple external oblique radiographs for diagnosis of Bosworth-type fracture. Methods : We reviewed the 327 patients who were diagnosed as unilateral malleolus ankle fracture in 2002 to 2012. Four cases of Bosworth-type fracture were identified. External oblique radiograph was taken initially, immediately after first closed reduction, and after open reduction (3 phases) was undertaken to check the position of fibula in relation with the talus. Fifty cases of bimalleolar fractures and unaffected ankle were compared. Longitudinal bisecting line along the proximal fibula was drawn, and the talus was divided in 2 parts. Anterior and posterior part of the talus was defined as part α and β. The ratio resulted from dividing α with (α + β) implies the fibula position relative to the talus. Results : Mean α/(α + β) ratio of each phase were 0.4994, 0.4891, 0.2875, 0.2698, and 0.2709. There was significant difference in initial and first reduction phase of Bosworth-type fracture than other groups (P = < .0001). There was no significant difference in open reduced Bosworth-type fracture with bimalleolar fractures and unaffected ankles (P = .528, .602). Conclusions : An external oblique radiograph provides useful information that can differentiate Bosworth-type fracture from other reducible bimalleolar fractures.ope

Association Between Excessive Joint Laxity and a Wider Hill-Sachs Lesion in Anterior Shoulder Instability

Background: Excessive general joint laxity, a negative prognostic factor in joint instability, has not been studied to determine its relationship with bipolar bone loss in anterior shoulder instability. Purpose/hypothesis: This study aimed to investigate the characteristics of bipolar bone defects in the presence of excessive joint laxity and the clinical outcomes based on the on-track/off-track theory. We hypothesized that (1) patients with excessive joint laxity might have less significant bipolar bone defects compared with those without excessive joint laxity and (2) no significant difference would be found in the clinical outcomes, including recurrence rate. Study design: Cohort study; Level of evidence, 3. Methods: This study included 81 patients who had undergone arthroscopic Bankart repair, with (group L; n = 33) or without (group N; n = 48) excessive joint laxity. The presence of excessive joint laxity was defined as a score of ≥4 using Beighton and Horan criteria preoperatively. Bipolar bone lesions were assessed using preoperative 3-dimensional computed tomography. Additional remplissage was performed for cases with off-track or positive engagement test in borderline on-track lesions. The functional outcomes at the 2-year follow-up were assessed using the recurrence rate, Subjective Shoulder Value, Rowe score, University of California Los Angeles shoulder score, active range of motion, and the sports/recreation activity level. Results: No significant difference was found in the glenoid bone defect between groups (14.1%, group L; 14.4%, group N). Off-track lesions were identified in 39.4% (13/33) of group L and 14.6% (7/48) of group N (P = .011). The mean Hill-Sachs interval to glenoid track ratio was 83.1% in group L and 75.2% in group N (P = .021). Additional remplissage procedures were more frequently performed in group L (48.5%; 16/33) than in group N (16.7%; 8/48) (P = .002). However, no significant difference was observed in the shoulder functional scores and recurrence rates between the groups. Conclusion: Patients with anterior shoulder instability and excessive joint laxity had significantly wider Hill-Sachs lesions and more off-track lesions than did those with normal joint laxity despite the lack of a significant difference in the glenoid bone defect. However, these differences in the Hill-Sachs lesion were not related to differences in the functional outcomes between the groups.restrictio

Biomechanical evaluation of a modified proximal humeral locking plate application for distal extra-articular diaphyseal humeral fractures

The extra-articular distal humerus locking plate (EADHP) is widely used for distal extra-articular diaphyseal humeral fracture fixation. However, it occasionally causes skin prominence and discomfort. The upside-down use of a proximal humerus internal locking system (PHILOS) plate is suggested as an alternative option, but it lacks biomechanical evidence. The purpose of this study was to compare the biomechanical performance between two different fixation methods: the modified use of the PHILOS plate on the anterior cortex versus conventional use of an EADHP on the posterior cortex. Twelve pairs of fresh-frozen cadaveric humeri were used and 7 mm gap osteotomy was performed at 50 mm proximal to the lateral epicondyle to simulate an AO/OTA 12-C1.3 fracture type. Single load to failure was measured after five stiffness tests of the plate-bone constructs in anterior/posterior bending, internal/external torsion, and axial compression. There were no significant differences in metrics between the two groups, except for the load to failure in posterior bending, which was significantly higher for PHILOS (1589.3 ± 234.5) compared to EADHP (1430.1 ± 188.6), p < .023. In conclusion, the modified use of the PHILOS plate showed comparable biomechanical performance compared to the conventional EADHP. The new fixation method offers potential clinical advantages, considering the patient's position and surgical approach at the time of surgery as well as postoperative soft tissue irritation. Therefore, this could be an option for distal humeral extra-articular diaphyseal fracture fixation when the use of EADHP is not suitable or preferred.restrictio