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PURPOSE: To investigate the stabilizing role of the long head of the biceps (LHB) for different simulated rotator cuff (RC) tears. METHODS: Human cadaveric specimens (n = 8) were fixed in a robotic-based experimental setup with a static loading of the RC, deltoid, and the LHB. RC tears were simulated by unloading of the corresponding muscles. A throwing motion and an anterior load-and-shift test were simulated under different RC conditions by unloading the supraspinatus (SS), subscapularis (SSc), infraspinatus (IS), and combinations (SS + SSc, SS + IS, SS + SSc + IS). The LHB was tested in 3 conditions: unloaded, loaded, and tenotomy. Translation of the humeral head and anterior forces depending on loading of the RC and the LHB was captured. RESULTS: Loading of LHB produced no significant changes in anterior force or glenohumeral translation for the intact RC or a simulated SS tear. However, if SSc or IS were unloaded, LHB loading resulted in a significant increase of anterior force ranging from 3.9 N (P = .013, SSc unloaded) to 5.2 N (P = .001, simulated massive tear) and glenohumeral translation ranging from 2.4 mm (P = .0078, SSc unloaded) to 7.4 mm (P = .0078, simulated massive tear) compared to the unloaded LHB. Tenotomy of the LHB led to a significant increase in glenohumeral translation compared to the unloaded LHB in case of combined SS + SSc (2.6 mm, P = .0391) and simulated massive tears of all SS + SSc + IS (4.6 mm, P = .0078). Highest translation was observed in simulated massive tears between loaded LHB and tenotomy (8.1 mm, P = .0078). CONCLUSIONS: Once SSc or IS is simulated to be torn, the LHB has a stabilizing effect for the glenohumeral joint and counteracts humeral translation. With a fully loaded RC, LHB loading has no influence. CLINICAL RELEVANCE: With an intact RC, the condition of the LHB showed no biomechanical effect on the joint stability. Therefore, from a biomechanical point of view, the LHB could be removed from the joint when the RC is intact or reconstructable. However, since there was a positive effect even of the unloaded LHB in this study when SSc or IS is deficient, techniques with preservation of the supraglenoid LHB origin may be of benefit in such cases.
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Lacerações , Lesões do Manguito Rotador , Articulação do Ombro , Humanos , Manguito Rotador/cirurgia , Manguito Rotador/fisiologia , Articulação do Ombro/cirurgia , Articulação do Ombro/fisiologia , Lesões do Manguito Rotador/cirurgia , Músculo Esquelético , Cabeça do Úmero/cirurgiaRESUMO
INTRODUCTION: Hitherto, the decision-making process for treatment of proximal humerus fractures (PHF) remains controversial, with no established or commonly used treatment regimens. Identifying fracture- and patient-related factors that influence treatment decisions is crucial for the development of such treatment algorithms. The objective of this study was to define a Delphi consensus of clinically relevant fracture- and patient-related factors of PHF for clinical application and scientific research. METHODS: An online survey was conducted among an international panel of preselected experienced shoulder surgeons. An evidence-based list of fracture-related and patient-related factors affecting treatment outcome after PHF was generated and reviewed by the members of the committee through online surveys. The proposed factors were revised for definitions, and suggestions from the first round mentioned in the free text were included as possible factors in the second round of surveys. Consensus was defined as having at least a two-thirds majority agreement. RESULTS: The Delphi consensus panel consisted of 18 shoulder surgeons who completed 2 rounds of online surveys. There was an agreement of more than two-thirds of the panel for three fracture-related factors affecting treatment decision in the case of PHF: head-split fracture, dislocated tuberosities, and fracture dislocation. Of all patient-related factors, a two-thirds consensus was reached for two factors: age and rotator cuff tear arthropathy. CONCLUSION: This study successfully conducted a Delphi consensus on factors influencing decision-making in the treatment of proximal humeral fractures. The documented factors will be useful for clinical evaluation and scientific validation in future studies.
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Fraturas do Úmero , Fraturas do Ombro , Humanos , Consenso , Técnica Delphi , Resultado do Tratamento , Fraturas do Ombro/cirurgiaRESUMO
INTRODUCTION: The number of atraumatic stress fractures of the scapular spine associated with reverse shoulder arthroplasty is increasing. At present, there is no consensus regarding the optimal treatment strategy. Due to the already weakened bone, fractures of the scapular spine require a high fixation stability. Higher fixation strength may be achieved by double plating. The aim of this study was to evaluate the biomechanical principles of double plating in comparison to single plating for scapular spine fractures. METHODS: In this study, eight pairs (n = 16) of human shoulders were randomised pairwise into two groups. After an osteotomy at the level of the spinoglenoid notch, one side of each pair received fracture fixation with a single 3.5 LCP (Locking Compression Plate) plate. The contralateral scapular spine was fixed with a 3.5 LCP and an additional 2.7 LCP plate in 90-90 configuration. The biomechanical test protocol consisted of 700 cycles of dynamic loading and a load-to-failure test with a servohydraulic testing machine. Failure was defined as macroscopic catastrophic failure (screw cut-out, plate breakage). The focus was set on the results of specimens with osteoporotic bone quality. RESULTS: In specimens with an osteoporotic bone mineral density (BMD; n = 12), the mean failure load was significantly higher for the double plate group compared to single plating (471 N vs. 328 N; p = 0.029). Analysis of all specimens (n = 16) including four specimens without osteoporotic BMD revealed no significant differences regarding stiffness and failure load (p > 0.05). CONCLUSION: Double plating may provide higher fixation strength in osteoporotic bone in comparison to a single plate alone. This finding is of particular relevance for fixation of scapular spine fractures following reverse shoulder arthroplasty. LEVEL OF EVIDENCE: Controlled laboratory study.
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Osteoporose , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Fenômenos Biomecânicos , Placas Ósseas , Cadáver , Fixação Interna de Fraturas/métodos , Humanos , Fraturas por Osteoporose/cirurgiaRESUMO
PURPOSE: Surgical treatment of shoulder instability caused by anterior glenoid bone loss is based on a critical threshold of the defect size. Recent studies indicate that the glenoid concavity is essential for glenohumeral stability. However, biomechanical proof of this principle is lacking. The aim of this study was to evaluate whether glenoid concavity allows a more precise assessment of glenohumeral stability than the defect size alone. METHODS: The stability ratio (SR) is a biomechanical estimate of glenohumeral stability. It is defined as the maximum dislocating force the joint can resist related to a medial compression force. This ratio was determined for 17 human cadaveric glenoids in a robotic test setup depending on osteochondral concavity and anterior defect size. Bony defects were created gradually, and a 3D measuring arm was used for morphometric measurements. The influence of defect size and concavity on the SR was examined using linear models. In addition, the morphometrical-based bony shoulder stability ratio (BSSR) was evaluated to prove its suitability for estimation of glenohumeral stability independent of defect size. RESULTS: Glenoid concavity is a significant predictor for the SR, while the defect size provides minor informative value. The linear model featured a high goodness of fit with a determination coefficient of R2 = 0.98, indicating that 98% of the SR is predictable by concavity and defect size. The low mean squared error (MSE) of 4.2% proved a precise estimation of the SR. Defect size as an exclusive predictor in the linear model reduced R2 to 0.9 and increased the MSE to 25.7%. Furthermore, the loss of SR with increasing defect size was shown to be significantly dependent on the initial concavity. The BSSR as a single predictor for glenohumeral stability led to highest precision with MSE = 3.4%. CONCLUSION: Glenoid concavity is a crucial factor for the SR. Independent of the defect size, the computable BSSR is a precise biomechanical estimate of the measured SR. The inclusion of glenoid concavity has the potential to influence clinical decision-making for an improved and personalised treatment of glenohumeral instability with anterior glenoid bone loss.
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Cavidade Glenoide , Instabilidade Articular , Luxação do Ombro , Articulação do Ombro , Fenômenos Biomecânicos , Cadáver , Cavidade Glenoide/diagnóstico por imagem , Cavidade Glenoide/cirurgia , Humanos , Instabilidade Articular/cirurgia , Ombro , Articulação do Ombro/cirurgiaRESUMO
BACKGROUND: Fractures of the proximal humerus are common. The most frequent surgical treatment option is open reduction and locking plate fixation. Multifragmentary fractures, including 3- and 4-part fractures, are especially challenging to treat because they correlate with an increased risk of fixation failure. In the past, several mechanisms of additional fixation were investigated, but none directly addressed the lesser tuberosity (LT). The goal of this study was to investigate the biomechanical impact of additional anterior fracture fixation in lateral locked plating (LLP) of 4-part proximal humeral fractures (PHFs). METHODS: Twenty-seven fresh frozen human shoulder specimens (mean age, 80 years) with intact rotator cuffs (RCs) were randomized into 4 groups: 3-part PHF with LLP and RC cerclage (n = 6); 4-part PHF with LLP and RC cerclage as standard of care (n = 7); 4-part PHF with LLP, RC cerclage, and 2 anterior 3.5-mm cortical screws (n = 7); and 4-part PHF with LLP, RC cerclage, and additional anterior one-third tubular plate (additional anterior plating [AAP], n = 7). Static load of the RC was simulated with weights. A force-controlled cyclic loading test was performed with a servo-hydraulic testing machine, followed by load-to-failure testing. An optical motion capture system recorded humeral head range of motion. RESULTS: LLP of a 4-part PHF showed more humeral head motion than LLP of a 3-part PHF without fracture of the LT (P < .001). Fixing the LT to the humeral head with two 3.5-mm screws significantly reduced humeral head motion compared with LLP with RC cerclage alone (P < .006). Using AAP significantly increased the construct stiffness compared with the standard of care (P = .03). CONCLUSION: LLP of a 4-part PHF is biomechanically less stable than LLP of a 3-part PHF without fracture of the LT. Additional screw fixation of the LT in 4-part PHFs improves stability compared with LLP alone. In case of metaphyseal comminution, AAP is favorable from a biomechanical perspective.
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Fraturas do Ombro , Ombro , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Placas Ósseas , Parafusos Ósseos , Fixação Interna de Fraturas , Humanos , Cabeça do Úmero/diagnóstico por imagem , Cabeça do Úmero/cirurgia , Fraturas do Ombro/diagnóstico por imagem , Fraturas do Ombro/cirurgiaRESUMO
Posttraumatic stiffness of the shoulder joint is a frequent and socioeconomically relevant result of injury; however, prior to making the diagnosis as the only cause of a persisting impairment of motion, it is necessary to rule out other sequelae of trauma. Even intensive conservative treatment is mostly accompanied by the stagnation of the impairments of movement. In many cases the treatment of choice is early arthroscopic arthrolysis with a standardized approach and intensive follow-up treatment. In the surgical treatment of proximal humeral fractures with humeral head preservation, arthroscopic arthrolysis with simultaneous implant removal is a form of planned second intervention for improvement of shoulder function in cases of persisting motion deficits after bony consolidation. Despite sometimes substantial limitations of movement, a clinically relevant and lasting improvement of shoulder function can be achieved with arthroscopic arthrolysis in posttraumatic shoulder stiffness.
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Artropatias , Fraturas do Ombro , Articulação do Ombro , Remoção de Dispositivo , Humanos , Amplitude de Movimento Articular , Ombro , Fraturas do Ombro/diagnóstico por imagem , Fraturas do Ombro/cirurgia , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/cirurgia , Resultado do TratamentoRESUMO
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RESUMO
The development of the numbers of cases involved in accident insurance consultant procedures (DAV), injury type procedures (VAV) and severe injury type procedures (SAV) after the introduction of the new injury type catalogue from 1 July 2018 is presented. Furthermore, possible alterations to organizational aspects, such as operating room times and average duration of hospitalization are presented. A first critical assessment of the modifications in the new catalogue was carried out, particularly with reference to the newly introduced section on complications (section 11). METHODS: A retrospective study of all inpatients treated in the context of the DAV, VAV and SAV procedures at a SAV center from the 2nd and 3rd quarters of 2018 was carried out. The development of the number of cases, the case mix index (CMI), the mean number of operations, the mean time in the operating room and the length of hospitalization were analyzed. Furthermore, an assessment of the SAV cases was carried out with respect to the new developments and with particularly reference to complications. RESULTS: The total number of inpatients in the context of the DAV, VAV, SAV procedures changed only slightly. There was a clear decrease in DAV cases and a relevant increase in SAV cases. The CMI increased by 47%, the number of surgical procedures by 15%, the mean time in the operating room by 36% and the length of hospitalization by 43%. When converted to a daily operating room unit of 7â¯h (Tagestischeinheit, TTE) the operating room time increased from 89 to 108 TTE and the length of hospitalization increased from 1028 to 1358 days. Of the 111 SAV cases in the 3rd quarter, 52% were assigned to the catalogue number 11 "complications". In comparison to the previous version of the VAV/SAV catalogue, it was now possible to assign all inpatients to a single category. CONCLUSION: The modifications of the VAV in the observational period led to an enormous increase in SAV cases. It remains to be seen whether this development is confirmed in subsequent quarters. The increase in CMI, the number of necessary operations, operating room times and duration of hospitalization showed the necessity of these innovations on structural changes of hospitals involved in the treatment of SAV cases.
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Grupos Diagnósticos Relacionados , Seguro de Acidentes , Hospitais , Salas Cirúrgicas , Estudos RetrospectivosRESUMO
INTRODUCTION: Complex radial head fractures are difficult to treat. In cases where stable fixation cannot be achieved, radial head resection or primary arthroplasty are frequently performed. Ex situ reconstruction of comminuted fractures may also be an option. This technique has widely been neglected in the literature, and only two small case series report satisfactory results. The aim of the present case series was to determine the functional and radiological outcomes of ex situ reconstructed Mason III and Mason IV fractures. We expect that the on-table reconstruction of comminuted radial head fractures will lead to bony union with no avascular necrosis in the postoperative course, which will demonstrate that this operative procedure is a reasonable option. PATIENTS AND METHODS: Two Mason type III and seven Mason type IV fractures (including four Monteggia-like lesions) were reconstructed ex situ. The mean age of the patients was 47 years (range 22-64). The clinical examination included RoM tests, elbow stability tests, and a neurological examination. The functional outcome was assessed with the MEPS and DASH score. The radiographic examination included a.p. and lateral views of the elbow to detect non-unions, inadequacy or loss of reduction, radial head necrosis, heterotopic ossifications and signs of posttraumatic arthritis. RESULTS: The mean follow-up time was 39 months (range 11-64). The mean MEPS was 82 points (range 15-100), and the mean DASH score was 20 points (range 0-85). All ex situ-reconstructed radial heads survived, and no signs of avascular necrosis were observed. Bony union was achieved in all but one patient who presented with an asymptomatic non-union. Signs of posttraumatic arthritis were found in all patients. With regard to the radial head, neither secondary resection nor arthroplasty had to be performed. All patients returned to their pre-injury occupations. CONCLUSION: Ex situ radial head reconstruction can be a reliable option in the surgical treatment of complex radial head fractures associated with severe elbow trauma. Even in the midterm follow-up, no signs of avascular necrosis were observed. Modern implants may even extend the indications for reconstruction in such cases. LEVEL OF EVIDENCE: Level IV-retrospective cohort study.
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Fraturas Cominutivas/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Fraturas do Rádio/cirurgia , Adulto , Artroplastia de Substituição/métodos , Articulação do Cotovelo/cirurgia , Epífises/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ossificação Heterotópica/cirurgia , Próteses e Implantes , Rádio (Anatomia)/cirurgia , Estudos Retrospectivos , Adulto JovemRESUMO
PURPOSE: Dynamic intraligamentary stabilization (DIS) has been introduced as a new technique to repair the torn anterior cruciate ligament (ACL) and to restore knee joint kinematics after an acute ACL tear. Aim of the present study was to compare the early post-operative activity, restoration of gait pattern and functional results after DIS in comparison with primary ACL reconstruction (ACLR) for acute ACL tears. It was hypothesized that functional results, post-operative activity and changes in gait pattern after DIS are comparable to those after ACLR. METHODS: Sixty patients with acute ACL tears were included in this study and underwent either DIS or ACLR with an anatomic semitendinosus autograft in a randomized manner. Patients were equipped with an accelerometric step counter for the first 6 weeks after surgery in order to monitor their early post-operative activity. 3D gait analysis was performed at 6 weeks and 6 months after surgery. Temporal-spatial, kinematic and kinetic parameters were extracted and averaged for each subject. Functional results were recorded at 6 weeks, 6 months and 12 months after surgery using the Tegner activity scale, International Knee Documentation Committee score and Lysholm score. RESULTS: Patients who underwent DIS showed an increased early post-operative activity with significant differences at week 2 and 3 (p = 0.0241 and 0.0220). No significant differences between groups were found for knee kinematic and kinetic parameters or the functional scores at any time of the follow-up. Furthermore, the difference in anterior tibial translation was not significantly different between the two groups (n.s.). CONCLUSION: Early functional results and changes in gait pattern after DIS are comparable to those of primary ACLR. Therefore, ACL repair may be an alternative to ACLR in this cohort of patients. LEVEL OF EVIDENCE: I.
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Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior/métodos , Marcha/fisiologia , Articulação do Joelho/fisiopatologia , Adolescente , Adulto , Lesões do Ligamento Cruzado Anterior/fisiopatologia , Fenômenos Biomecânicos , Feminino , Seguimentos , Humanos , Articulação do Joelho/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento , Adulto JovemRESUMO
PURPOSE: To analyze the ultimate failure load, yield load, stiffness, and cyclic resistance of different anterior cruciate ligament (ACL) soft tissue graft fixation techniques in osteopenic bone. METHODS: In this study, 24 fresh-frozen human cadaveric tibiae (mean age 82.6 years; range 56-96; 6 male and 6 female donors) were used. Quantitative computed tomography was performed to match bone density. Looped porcine flexor tendon grafts were chosen as ACL graft substitutes for tibial graft fixation techniques (n = 8 each): (1) hybrid fixation with an interference screw and extracortical button fixation; (2) extracortical button fixation; and (3) interference screw fixation. In single cycle mode, constructs were loaded to failure to evaluate stiffness, yield load, and maximum load. In cyclic testing, 2,000 cycles (25-100 N) were applied followed by loading to failure. A 1-way analysis of variance was performed with significance set at P = .05. RESULTS: Hybrid fixation resulted in significantly higher yield load (283.4 ± 86.19 N; P = .0037) and maximum load (407.9 ± 102.3 N; P = .0026) than interference screw fixation (yield load 176.4 ± 26.03, max load 231.8 ± 94.06 N) in elderly bone. Yield load after extracortical button fixation (252.9 ± 41.97 N; P = .0286) was also higher than that after interference screw fixation, but stiffness (18.98 ± 9.154 N/mm; P = .0041) was less than that after hybrid fixation (37.28 ± 13.53 N/mm). Of 8 specimens in the interference screw group, 7 did not survive 2,000 cycles and failed by graft slippage, whereas all other specimens in both other groups survived. CONCLUSIONS: Tibial hybrid fixation of ACL soft tissue grafts provides less vertical graft movement than extracortical button fixation and higher primary failure loads than interference screw fixation in elderly bone. CLINICAL RELEVANCE: In this elderly human joint in vitro model, tibial hybrid fixation provides biomechanical advantages over other techniques. Graft fixation with only an interference screw should be avoided in osteopenic bone.
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Lesões do Ligamento Cruzado Anterior/cirurgia , Parafusos Ósseos , Osteoporose , Tíbia/cirurgia , Implantes Absorvíveis , Idoso , Idoso de 80 Anos ou mais , Animais , Reconstrução do Ligamento Cruzado Anterior/métodos , Fenômenos Biomecânicos , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tendões/transplante , TransplantesRESUMO
PURPOSE: Dynamic intraligamentary stabilization (DIS) has been introduced for the repair of acute anterior cruciate ligament (ACL) tears as an alternative to delayed reconstruction. The aim of the present study was to compare knee joint kinematics after DIS to those of the ACL-intact and ACL-deficient knee under simulated Lachman/KT-1000 and pivot-shift tests. We hypothesized that DIS provides knee joint kinematics equivalent to an intact ACL. METHODS: With the use of a robotic knee simulator, knee kinematics were determined in simulated Lachman/KT-1000 and pivot-shift tests at 0°, 15°, 30°, 60°, and 90° of flexion in eight cadaveric knees under the following conditions: (1) intact ACL, (2) ACL deficiency, (3) DIS with a preload of 60 N, and (4) DIS with a preload of 80 N. Statistical analyses were performed using two-factor repeated-measures analysis of variance. The significance level was set at a p value of <0.05. RESULTS: After DIS with a preload of either 60 N or 80 N, the anterior translation was significantly reduced in the simulated Lachman/KT-1000 and pivot-shift tests when compared to the ACL-deficient knee (p < 0.05). No significant differences were observed between the DIS reconstruction with a preload of 80 N and the intact ACL with regard to anterior laxity in either test. However, DIS with a preload of only 60 N was not able to restore knee joint kinematics to that of an intact knee in all degrees of flexion. CONCLUSION: DIS with a preload of 80 N restores knee joint kinematics comparable to that of an ACL-intact knee and is therefore capable of providing knee joint stability during ACL healing. DIS therefore provides a new technique for primary ACL repair with superior biomechanical properties in comparison with other techniques that have been described previously, although further clinical studies are required to determine its usefulness in clinical settings.
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Reconstrução do Ligamento Cruzado Anterior/métodos , Articulação do Joelho/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos/fisiologia , Cadáver , Humanos , Instabilidade Articular/fisiopatologia , Instabilidade Articular/cirurgia , Articulação do Joelho/cirurgia , Pessoa de Meia-Idade , Exame Físico/métodosRESUMO
INTRODUCTION: Complications after internal fixation of proximal humerus fracture are common and may require surgical revision. Reverse total shoulder arthroplasty (RTSA) is frequently performed in such cases. The aim of the present study was to evaluate the functional results and complications after RTSA for the treatment of type I fracture sequelae after internal fixation of proximal humerus fractures. MATERIALS AND METHODS: 26 patients (18 female, 8 male) underwent surgical revision of type I fracture sequelae of the proximal humerus after locking plate (n = 22) or intramedullary nail (n = 4) fixation. The mean age of the patients at the time of the revision was 75 years (range 65-89). After a mean follow-up of 36 months (range 18-58), clinical examination was performed and the age- and gender-related Constant-Murley Score (CMS) and the Oxford Shoulder Score (OSS) were obtained from all patients and compared to the pre-revision values. RESULTS: The mean age- and gender-related CMS of the affected shoulder increased from 44% (range 17-65) to 73% (range 44-97). This difference was statistically significant (p < 0.001). The CMS of the unaffected shoulder was 93% (range 72-98). This relates to a ratio in the CMS of 78% between the affected and the contralateral shoulder. The mean OSS was 28 points (range 12-54) for the operated shoulder and 43 points (range 34-48) for the unaffected side, resulting in 66% ratio. Again, the OSS improved significantly when compared with the preoperative values (p < 0.001). A total of five complications including two periprosthetic fractures were observed and required surgical revision. CONCLUSION: Satisfying results can be obtained with RTSA as a salvage procedure for type I fracture sequelae after previous internal fixation of proximal humerus fractures.
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Artroplastia do Ombro/métodos , Fixação Interna de Fraturas/efeitos adversos , Complicações Pós-Operatórias/cirurgia , Reoperação , Fraturas do Ombro/cirurgia , Idoso , Idoso de 80 Anos ou mais , Pinos Ortopédicos , Placas Ósseas , Feminino , Humanos , Úmero/cirurgia , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
OBJECTIVES: The surgical treatment of comminuted fractures of the distal humerus remains a challenging problem. The aim of the present study was to compare the clinical outcomes of primary external fixation with second-staged open reduction and internal fixation (ORIF) and initial definitive internal fixation in surgically treated patients with comminuted distal humerus fractures. DESIGN: Retrospective comparative study. SETTING: Level one trauma center. PATIENTS: A total of 24 patients (median age 52 years; range 14-84 years) were included: 15 patients were treated with initial definitive internal fixation with pre-contoured locking compression plates (group A), and 9 patients underwent surgical treatment with primary external fixation and second-staged ORIF (group B). Only patients with C3 fractures according to the AO classification were included in the study. MAIN OUTCOME MEASUREMENT: Disability of the Arm, Shoulder and Hand (DASH) and Mayo Elbow Performance Score (MEPS). INTERVENTION: External fixation internal fixation with locking plates. RESULTS: The median follow-up was 37 months for both groups. There was a significantly higher median elbow extension deficit in group B (39°) compared to group A (17°) (p = 0.048). The mean DASH score in group A was 14 and 12.5 in group B. MEPS showed that more patients in group A achieved excellent results; however, there was no significant difference compared to group B. CONCLUSIONS: Primary external fixation with second-staged ORIF demonstrated a higher complication rate and significantly greater loss of extension compared with initial definitive internal fixation. Thus, the use of primary external fixation in cases of comminuted distal humerus fractures appears to have a negative influence on the patient outcomes. LEVEL OF EVIDENCE: Therapeutic level III.
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Fixadores Externos , Fixação Interna de Fraturas/métodos , Fraturas Cominutivas/cirurgia , Fraturas do Úmero/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Placas Ósseas , Articulação do Cotovelo/cirurgia , Fixadores Externos/efeitos adversos , Feminino , Seguimentos , Fixação Interna de Fraturas/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Redução Aberta , Complicações Pós-Operatórias , Reoperação , Estudos Retrospectivos , Resultado do Tratamento , Adulto JovemRESUMO
INTRODUCTION: The high rigidity of metal implants may be a cause of failure after fixation of proximal humerus fractures. Carbon fiber-reinforced polyetheretherketone (PEEK) plates with a modulus similar to human cortical bone may help to overcome this problem. The present study assesses the biomechanical behavior of a PEEK plate compared with a titanium locking plate. MATERIALS AND METHODS: Unstable two- and three-part fractures were simulated in 12 pairs of cadaveric humeri and were fixed with either a PEEK or a titanium locking plate using a pairwise comparison. With an optical motion capture system, the stiffness, failure load, plate bending, and the relative motion at the bone-implant interface and at the fracture site were evaluated. RESULTS: The mean load to failure for two- and three-part fracture fixations was, respectively, 191 N (range 102-356 N) and 142 N (range 102-169 N) in the PEEK plate group compared with 286 N (range 191-395 N) and 258 N (range 155-366 N) in the titanium locking plate group. The PEEK plate showed significantly more bending in both the two- and three-part fractures (p < 0.05), an increased relative motion at the bone-implant interface and lower stiffness values (p < 0.05). CONCLUSION: In this biomechanical study on unstable proximal humerus fractures, fixation with a PEEK plate showed lower fixation strength and increased motion at the bone-implant interface compared with a titanium locking plate.
Assuntos
Materiais Biocompatíveis , Placas Ósseas , Fixação Interna de Fraturas/instrumentação , Cetonas , Polietilenoglicóis , Fraturas do Ombro/cirurgia , Titânio , Idoso , Idoso de 80 Anos ou mais , Benzofenonas , Fenômenos Biomecânicos , Cadáver , Carbono , Fibra de Carbono , Feminino , Humanos , Masculino , Polímeros , Estresse MecânicoRESUMO
PURPOSE: To kinematically and biomechanically compare 4 different types of tibial tunnel management in single-stage anterior cruciate ligament (ACL) revision reconstruction with the control: primary ACL reconstruction using a robotic-based knee testing setup. METHODS: Porcine knees and flexor tendons were used. One hundred specimens were randomly assigned to 5 testing groups: (1) open tibial tunnel, (2) bone plug technique, (3) biodegradable interference screw, (4) dilatation technique, and (5) primary ACL reconstruction. A robotic/universal force-moment sensor testing system was used to simulate the KT-1000 (MEDmetric, San Diego, CA) and pivot-shift tests. Cyclic loading and load-to-failure testing were performed. RESULTS: Anterior tibial translation increased significantly with all of the techniques compared with the intact ACL (P < .05). In the simulated KT-1000 test, groups 2 and 3 achieved results equal to those of primary ACL reconstruction (P > .05). The open tunnel and dilated tunnel techniques showed significantly greater anterior tibial translation (P < .05). The results of the simulated pivot-shift test were in accordance with those of the KT-1000 test. No significant differences could be observed regarding stiffness or maximum load to failure. However, elongation was significantly lower in the primary ACL reconstruction group compared with groups 1 and 3 (P = .02 and P = .03, respectively). CONCLUSIONS: Filling an incomplete and incorrect tibial tunnel with a press-fit bone plug or a biodegradable interference screw in a standardized laboratory situation provided initial biomechanical properties and knee stability comparable with those of primary ACL reconstruction. In contrast, the dilatation technique or leaving the malplaced tunnel open did not restore knee kinematics adequately in this model. Backup extracortical fixation should be considered because the load to failure depends on the extracortical fixation when an undersized interference screw is used for aperture fixation. CLINICAL RELEVANCE: Our biomechanical results could help orthopaedic surgeons to optimize the results of primary ACL revision with incomplete, incorrect tunnel placement.
Assuntos
Reconstrução do Ligamento Cruzado Anterior/métodos , Ligamento Cruzado Anterior/cirurgia , Amplitude de Movimento Articular , Tíbia/cirurgia , Animais , Fenômenos Biomecânicos , Parafusos Ósseos , Articulação do Joelho/cirurgia , Reoperação , Robótica , Suínos , Tendões/cirurgiaRESUMO
PURPOSE: The aim of this study was to biomechanically assess patellar tendon repair techniques with additional cable wire or polydioxanone suture (PDS) cord augmentation in comparison with a suture-anchor repair technique. METHODS: Patellar tendon repair was performed in 60 specimens using a porcine bone model. Yield load, maximum load, stiffness and elongation of patellar tendon reconstructions with (1) cable wire augmentation, (2) PDS cord augmentation or (3) suture anchor repair were evaluated using a cyclic loading and load-to-failure test setup. RESULTS: In comparison with suture anchor repair, augmentation of the reconstruction with either cable wires or PDS cords provides significantly higher maximum loads (527 and 460 N vs. 301 N; p < 0.01 and p = 0,012, respectively) under load-to-failure testing and less elongation (8.81 mm ± 1.55 mm and 10.56 mm ± 3.1 mm vs. 18.38 mm ± 7.51 mm; p = 0.037 and p = 0.033, respectively) under cyclic loading conditions. CONCLUSION: Augmentation of a patellar tendon repair with either a cable wire or a PDS cord provides higher primary stability than suture anchor repair in patellar tendon ruptures. The study supports the use of additional augmentation of a tendon repair in the clinical setting in order to prevent loss of reduction and allow for early post-operative mobilisation.
Assuntos
Traumatismos do Joelho/cirurgia , Patela/cirurgia , Ligamento Patelar/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Animais , Fenômenos Biomecânicos , Deambulação Precoce , Humanos , Período Pós-Operatório , Âncoras de Sutura , Técnicas de Sutura , Suturas , Suínos , Traumatismos dos Tendões/cirurgiaRESUMO
INTRODUCTION: Aim of this study was to investigate the accuracy of a conventional over-the-top-guide (OTG) with a typically short offset to hit the center of the native femoral ACL footprint through the anteromedial portal in comparison to a specific medial-portal-aimer (MPA) with larger offset. MATERIALS AND METHODS: In 20 matched human cadaveric knees, insertion sites of the ACL were marked in medial arthrotomy. An OTG with an offset of 5.5 mm, respectively, the MPA with 9 mm offset was used in a medial portal approach to locate the center of a single bundle ACL reconstruction tunnel with k-wires. Distances from the footprint center, the OTG drilling and the MPA drilling to the roof of the intercondylar notch and to the deep cartilage margin were determined. After positioning of radiological markers, radiographic analysis was performed according to the quadrant technique as described by Bernard and Hertel. RESULTS: The distance from ACL origin to the roof of the notch was 10.3 (±2.1) mm, in the OTG group 6.7 (±1.5) mm and in the MPA group 9.6 (±1.9) mm. The distance to the deep cartilage margin was 9.5 (±1.7) mm from ACL origin, 4.8 (±1.3) mm with OTG and 8.7 (±1.4) mm with MPA. There were statistically significant differences between the distances of the footprint center and the OTG group after measuring and also after radiographic analysis (p < 0.0001). Using the MPA, no significant different distances in comparison to the anatomical ACL center were found (p > 0.0001). There was an increased risk for femoral blow (9/10 vs. 0/10) in the OTG group after overdrilling with a 9 mm drill. CONCLUSION: Short (5.5 mm) offset femoral aiming devices fail to locate the native ACL footprint center in medial portal approach with an increased risk for femoral blowout when overdrilling. The special medial-portal-aiming device with 9 mm offset hit the center reliably.
Assuntos
Reconstrução do Ligamento Cruzado Anterior/instrumentação , Ligamento Cruzado Anterior/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Ligamento Cruzado Anterior/anatomia & histologia , Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior/métodos , Fêmur/anatomia & histologia , Fêmur/cirurgia , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Tíbia/anatomia & histologia , Tíbia/cirurgiaRESUMO
PURPOSE: Aim of the present study was to evaluate the risk factors for the failure of coracoclavicular ligament reconstruction using a flip button repair technique and to analyse complications related to this procedure. METHODS: Seventy-one patients (3 female, 68 male) underwent surgical treatment using a flip button repair technique for an acute acromioclavicular joint dislocation. The following factors and its impact on clinical and radiographic outcome were assessed: age at trauma, interval between trauma and surgery, degree of displacement (according to Rockwood's classification), coracoid button position, button migration and post-operative appearance of ossifications. RESULTS: Sixty-three patients were available for follow-up. The overall Constant score was 95.2 points (range 61-100 points) compared to 97 points (range 73-100 points) for the contralateral side (p = 0.05). Nine patients (14.3 %) needed surgical revision. Inappropriate positioning of the coracoid bone tunnel with subsequent button dislocation was the most frequently observed mode of failure (6 cases, 9.5 %). Button migration into the clavicle was associated with loss of reduction (p = 0.02). The patient's age at the time of trauma had a significant impact on the clinical outcome, whereas younger patients achieved better results (p = 0.02). The interval between trauma and surgery did not significantly affect the outcome (n.s.). CONCLUSION: Good to excellent clinical results can be achieved with the presented surgical technique. The age of the patient at trauma had a significant influence on the functional outcome. Furthermore, placement of the coracoid button centrally under the coracoid base is crucial to prevent failure. LEVEL OF EVIDENCE: IV.
Assuntos
Articulação Acromioclavicular/lesões , Luxações Articulares/cirurgia , Ligamentos Articulares/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Procedimentos de Cirurgia Plástica/métodos , Complicações Pós-Operatórias , Articulação Acromioclavicular/cirurgia , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Luxação do Ombro/cirurgia , Fatores de Tempo , Adulto JovemRESUMO
BACKGROUND: A radiolucent carbon fiber-reinforced polyetheretherketone (CFR-PEEK) plate was recently introduced for fixation of proximal humerus fractures. Prospective clinical and radiographic results of patients treated with a CFR-PEEK plate are compared with those of patients treated with a conventional locking plate. METHODS: Twenty-nine patients (mean age, 66 years) were treated with a CFR-PEEK plate for a 3- or 4-part proximal humerus fracture. Patients were clinically and radiographically re-examined at 6 weeks, 6 months, 12 months, and 24 months with the Simple Shoulder Test, Constant-Murley score (CMS), and Oxford Shoulder Score (OSS) as well as with simple radiographs. In addition, results were compared with a matched group of patients treated with a conventional locking plate. RESULTS: At the final follow-up examination at 24 months, patients achieved a mean Simple Shoulder Test score of 58%, a mean CMS of 71.3 points (range, 44-97), and a mean OSS of 27.4 points (range, 8-45). Bone union was confirmed in all patients. Compared with patients treated with the conventional locking plate, patients treated with the CFR-PEEK plate achieved significantly better results with regard to the CMS and the OSS (P = .038 and .029, respectively). Furthermore, loss of reduction with subsequent varus deformity was less frequently observed in the CFR-PEEK plate group. CONCLUSION: Fixation of proximal humerus fractures with a CFR-PEEK plate provides satisfying clinical and radiographic results after 2 years of follow-up. The results are comparable to those achieved with conventional locking plates.