Orthopaedic and Trauma Surgery

Investigation of thermally induced damage to surrounding nerve tissue when using curettage and cementation of long bone tumours, modelled in cadaveric porcine femurs Abstract Introduction Curettage with cement augmentation is a technique used in the treatment of bone tumours. Thermal energy released during the cement polymerisation process can damage surrounding tissues. This study aims to record temperature changes at various sites on and around bone during the cementing process. We hypothesised that adjacent structures, such as the radial nerve, may be threatened by this process in the clinical setting. Materials and methods Using 18 porcine femurs as a model of the human humerus, we used thermocouples and a thermal imaging camera to measure changes in temperature during the cementing process. Fractures were created in nine samples to establish whether a discontinuity of the cortex had an effect on thermal conduction. Results Significantly higher temperatures were recorded in samples with a fracture compared to those without a fracture. The site overlying the centre of the cement bolus (hypothetical site of the radial nerve) demonstrated higher temperatures than all other sites on the same cortex. When considering the radial nerve site, over half the samples demonstrated temperatures exceeding 47 °C for over a minute. When a threshold of 50 °C for more than 30 s was considered, three samples without a fracture exceeded this value compared to two with a fracture. Conclusion The temperatures recorded were sufficient to cause damage to neural tissue. Limiting thermal exposure to soft tissues is recommended. Increased attention is required when using larger cement boluses, or where bone quality is poor or a fracture, iatrogenic or preexisting, is present.

Clinical outcomes and survival rate of autologous chondrocyte implantation with and without concomitant meniscus allograft transplantation: 10- to 15-year follow-up study Abstract Purpose The purpose of this study was to compare the clinical outcomes and survival rate of autologous chondrocyte implantation (ACI) with or without concomitant meniscus allograft transplantation (MAT). Methods Patients who underwent ACI of the medial or lateral femoral condyle with or without concomitant MAT were retrospectively reviewed. There were 14 patients (mean age, 31.2 ± 9.9 years) who underwent isolated ACI and 19 patients who underwent ACI with concomitant MAT (mean age, 34.8 ± 8.4 years). The International Knee Documentation Committee (IKDC) subjective score, Lysholm score, Tegner activity score, and 10- to 15-year survival rate were compared between groups. Results All clinical scores showed significant improvement postoperatively in both groups. At final follow-up, the IKDC subjective score was superior in isolated ACI (75.8 ± 18.4) compared to ACI with MAT (61.0 ± 16.6, p = 0.024). The Lysholm score was also higher in isolated ACI (77.5 ± 19.1) than ACI with MAT (62.5 ± 18.1, p = 0.029). The Tegner activity score did not differ between treatments (isolated ACI, 5.3 ± 1.1; ACI with MAT, 4.5 ± 1.3; p = 0.072). The 15-year survival rate for isolated ACI was higher than that of ACI with concomitant MAT (69.6% vs 50.2%), but this difference was not statistically significant (p = 0.19). Conclusions ACI with concomitant MAT did not restore clinical outcomes as much as isolated ACI. There was a trend for the long-term survival rate to be greater in isolated ACI than ACI with MAT. These results should be considered in planning for the treatment of focal chondral defect with meniscus deficiency. Level of study Retrospective comparative trial; level of evidence, 3.

Augmentation of plate osteosynthesis for proximal humeral fractures: a systematic review of current biomechanical and clinical studies Abstract Introduction Secondary dislocation due to loss of fixation is the most common complication after plate fixation of proximal humeral fractures. A wide range of different techniques for augmentation has been described to improve the primary and secondary stability. Nevertheless, comparative analyses on the specific advantages and limitations are missing. Therefore, the aim of the present article was to systematically review and evaluate the current biomechanical and clinical studies. Materials and methods The databases of PubMed and EMBASE were comprehensively searched for studies on augmentation techniques for proximal humeral fractures using defined search terms. Subsequently, all articles identified were screened for eligibility and subdivided in either clinical or biomechanical studies. Furthermore, the level of evidence and study quality were assessed according the Oxford Centre for Evidence-Based Medicine and the Coleman Methodology Score, respectively. Results Out of 2788, 15 biomechanical and 30 clinical studies were included. The most common techniques were structural allogenic or autologous bone grafting to enhance the medial support, metaphyseal void filling utilizing synthetic bone substitutes or bone grafts, and screw-tip augmentation with bone cement. Biomechanical data were available for structural bone grafting to enhance the medial support, void filling with synthetic bone substitutes, as well as for screw-tip augmentation. Clinical evidence ranged from level II–IV and study quality was 26–70/100 points. Only one clinical study was found investigating screw-tip augmentation. All studies included revealed that any kind of augmentation positively enhances mechanical stability, reduces the rate of secondary dislocation, and improves patients’ clinical outcome. None of the studies showed relevant augmentation-associated complication rates. Conclusions Augmentation of plate fixation for proximal humeral fractures seems to be a reliable and safe procedure. All common techniques mechanically increase the constructs’ stability. Clinically evaluated procedures show reduced complication rates and improved patient outcomes. Augmentation techniques seem to have the highest significance in situations of reduced bone mineral density and in high-risk fractures, such as 4-part fractures. However, more high-quality and comparative clinical trials are needed to give evidence-based treatment recommendations.

The prevalence of a prominent anterior inferior iliac spine Abstract Introduction Impingement of the prominent anterior inferior iliac spine (AIIS) against the femoral neck has recently been described as another type of impingement. The purpose of this study is to provide a distribution of AIIS types using the classification proposed by Hetsroni and thus report on the prevalence of prominent types. Materials and methods A total of 400 patients were included in the study with an average age 27.3 ± 6.9 years (range 18–40). All patients received a whole-body polytrauma computer tomography (CT) scan in the emergency room (ER) upon arrival. The classification of AIIS proposed by Hetsroni et al., which describes three morphological types, was used. Type II and III were grouped as prominent types. The measurements were performed in all three planes by two examiners. Results Male to female ratio was 71:29. Type I was observed in 367 (91.7%) patients. Type II was observed in 31 (7.8%) patients and type III was observed in 2 (0.5%) patients, unilaterally. Prominent types were much more prevalent in men (10.5%) than in women (2.6%). The CT assessment demonstrated excellent intra- and interreliability (overall: 0.926, I/II: 0.906, III: 1.000). Conclusion A young population demonstrates a prevalence of a prominent AIIS of 11.5%. Prominent AIIS is more common in men than in women.

Acetabular revision arthroplasty using press-fitted jumbo cups: an average 10-year follow-up study Abstract Introduction Acetabular revision arthroplasty using jumbo cups for moderate-to-severe acetabular defects has varied outcomes. We evaluated the clinical and radiological outcomes of acetabular revision arthroplasty using a press-fitted jumbo cup and sought to identify factors that influence outcomes during intermediate follow-up. Materials and methods Eighty patients (47 men, 33 women; 80 hips) who underwent acetabular revision arthroplasty using press-fitted jumbo cups were included. The mean follow-up period was 10.4 years. Harris hip score (HHS), presence of groin pain, radiographic results, and Kaplan–Meier survival curves were evaluated. Implant design and surgery-related and patient-related factors were assessed to identify influential factors for cup loosening. Migration and wear analyses were performed using Einzel-Bild-Röntgen-Analyse software. Results The mean preoperative HHS of 53 had improved to 77 at the final follow-up (p = 0.005). Nine patients experienced groin pain. Acetabular cup loosening was observed in seven cups (8.7%), and one jumbo cup was replaced with a reinforcement cage. The survival rate of the acetabular cup was 91% at 16 years according to the Kaplan–Meier analysis. Osteolysis was identified around the cup in six cases (7.5%). Acetabular cup loosening occurred more frequently in patients with conventional polyethylene liners than in those with highly cross-linked polyethylene liners (p = 0.045). The mean total migration was 1.52 mm, and the mean total wear was 0.98 mm. There was a positive correlation between total migration and total wear (p = 0.023; Spearman’s rho = 0.388). The mean wear rate of the patients with the cup inclination angle < 50° was significantly lower than those with the cup inclination angle > 50° (p = 0.001). There were four cases of complications (three dislocations and one infection) that did not require revision surgery. Conclusion Press-fitted jumbo cups for acetabular revision arthroplasty exhibited encouraging results during follow-up for an average of 10 years. Use of highly cross-linked polyethylene liners and proper placement of the acetabular component with an inclination angle < 50° may contribute to better clinical outcomes after acetabular revision arthroplasty with jumbo cups.

Long-term outcome of fingertip reconstruction with the homodigital neurovascular island flap Abstract Introduction Fingertip injuries are frequent and several surgical strategies exist to reconstruct the amputated part and restore function and appearance. Yet, long-term results are rarely published. The purpose of this study was to examine the long-term clinical outcome of neurovascular island flaps for traumatic fingertip amputation of Allen type III/IV injuries. Materials and methods We retrospectively analysed a cohort of patients with traumatic fingertip amputation that underwent reconstruction with a neurovascular island flap from January 2003 to December 2014. No mandatory splinting was applied after surgery. 28 participants (29 fingers) were available for follow-up at mean 8 years after reconstruction. Activities of daily living were measured with the disabilities of the arm, shoulder and hand questionnaire. Grip strength and finger motion were assessed using a Jamar dynamometer and a goniometer. Two-point discrimination and Semmes–Weinstein monofilaments were used to evaluate sensory recovery. Results No intraoperative complications occurred and all flaps survived. Mean flap size was 4.7 ± 0.6 cm2. Active motion of the fingers was over 95% of the contralateral side at follow-up. Three patients showed mild extension lag of the proximal interphalangeal joint. The grip strength of the affected hand and of each of the affected fingers was over 70% of the contralateral side. In comparison to the contralateral side we did not detect any significant difference for the Semmes–Weinstein monofilament test, but two-point discrimination (5.1 ± 1.7 mm) was significantly impaired. According to the Lim classification 1 of 14 nails with hook nail deformity showed grade 3 breaking of the nail. The DASH score was 16.0. All patients returned to their original occupation and patient satisfaction with the procedure was high. Conclusions The risk for disabling flexion contracture seems to be small even without mandatory splinting. Neurovascular island flaps for fingertip amputation of Allen type III/IV injuries are a reliable tool in fingertip reconstruction in the long term.

Primary versus revision arthroscopically-assisted acromio- and coracoclavicular stabilization of chronic AC-joint instability Abstract Background A gracilis tendon autograft with TightRope-augmentation can be used for arthroscopically-assisted acromioclavicular (AC)- and coracoclavicular (CC-)stabilization of chronic bidirectional AC-joint instability after failed primary treatment. The impact of failed initial treatment on postoperative outcome is unclear. Hence, the purpose of this study was to evaluate it. Methods Twenty-seven of 38 patients suffering from chronic AC-joint instability after either failed conservative (group 1) or surgical treatment (group 2) treated in the above-mentioned technique were finally included in this study. The Subjective Shoulder Value, the Constant Score, the Taft Score and the Acromioclavicular Joint Instability Score were used for clinical evaluation. Bilateral anteroposterior stress radiographs and bilateral Alexander views were obtained for radiological evaluation. Results 14 patients of group 1 [3f/11m; median age 47.6 (range 20.9–57.4) years] could be evaluated after a median follow-up of 24.3 (range 20–31.2) months and 13 patients of group 2 [6f/7m; median age 44.9 (range 24.9–61.0) years] were available after a median follow-up of 28.8 (range 20–33) months. Comparison of clinical score results revealed no significant differences between both groups. The median CC-difference showed no significant difference between the groups [group 1 0.8 (0–10.5) mm, group 2 0.9 (0–4.3) mm]. Conclusion AC- and CC-stabilization of chronic bidirectional AC-joint instability using a gracilis tendon autograft with TightRope-augmentation can be recommended after failed conservative and surgical treatment. Study design Retrospective cohort study; Level of evidence III.

A surgical algorithm for the management of recalcitrant distal femur nonunions based on distal femoral bone stock, fracture alignment, medial void, and stability of fixation Abstract Background Recalcitrant distal femur nonunions (RDFN) are a challenge in management due to factors including poor bone stock, multiple surgeries, metaphyseal bone loss, and joint contractures. There are no specific guidelines in the management of cases of RDFN. Based on our experience, we devised an algorithm and we present the results of 62 cases of RDFN managed following it. Materials and methods Our algorithm was formulated after analyzing 34 cases of RDFN and it involved four factors which were hypothesized to influence outcomes namely: distal femoral bone stock, extent of medial void, alignment of the fracture, and stability of fixation. Each factor was addressed specifically to achieve a good outcome. Between 2012 and 2015, 62 patients with RDFN at a mean age of 47.4 years (26–73) and 2.3 prior surgeries (2–6) were managed following the algorithm. Intervention 58 patients required revision osteosynthesis to improve alignment and achieve a stable fixation. 4 elderly patients with poor bone stock were managed with arthroplasty. Extent of medial void was found to significantly influence surgical decision making. Five patients without medial void required only cancellous autograft bone grafting, 47 patients with < 2 cm void were treated with an allograft fibular strut inserted in the metaphysis and 6 patients with a void > 2 cm were managed with medial plating. Outcomes and results 57 patients treated with osteosynthesis achieved union at an average of 7.4 months (6–11) and the 4 patients managed with arthroplasty also had a favourable outcome. One patient who was managed with revision osteosynthesis had a nonunion with an implant failure and needed an arthroplasty procedure. The average LEFS (lower extremity functional score) of all our patients was 67 (51–76) at an average follow-up of 18.2 months (12–33). Conclusion Our stepwise surgical algorithm would help surgeons to identify the factors that need to be addressed and guide them towards the interventions that are necessary to achieve a successful outcome while managing cases of RDFN. Level of evidence III. Level of clinical care Level I Tertiary trauma centre.

Posterior condylar resections in total knee arthroplasty: current standard instruments do not restore femoral condylar anatomy Abstract Introduction Correct femoral rotational alignment in total knee arthroplasty (TKA) is important for femoropatellar knee kinematics as well as for the overall clinical success. The goal of the present study was to evaluate how accurately standard instruments of various manufacturers with specific rotational settings in posterior referencing restore the posterior femoral condylar anatomy and allow a rotational alignment which matches a particular anatomic rotational landmark on CT. Methods The anatomical transepicondylar axis (aTEA) and the posterior condylar line (PCL) were identified and the angle formed by these two axes was measured on 100 consecutive CT scans of knees. A virtual posterior condylar resection was performed relative to the aTEA for femoral sizers of various manufacturers in different external rotations ranging from 3° to 7°. The resections of medial and lateral posterior condyle were calculated as well as the condylar twist angle (CTA) between PCL and aTEA. Results The posterior condylar resection varied between 9 mm and 14 mm on the medial side and between 4 mm and 10.5 mm on the lateral side. The mean CTA was 5.5° of internal rotation (SD ± 1.9°). External femoral rotation resulted in increased resection of the medial posterior condyle and decreased resection of the lateral posterior condyle. Conclusion Femoral sizers using a posterior referencing technique increase, with rising external rotation, medial posterior condylar resection to an extent that may exceed the implant thickness in the majority of systems. Surgeons should be aware that current standard instruments do not restore the anatomy of the posterior medial and lateral condyle and do not align the femoral component parallel to the aTEA, which may result in internal rotation of a symmetric femoral component.

Does the critical shoulder angle decrease after anterior acromioplasty? Abstract Introduction No clinical studies to date have analyzed the critical shoulder angle (CSA) following anterior acromioplasty. Our study’s main objective was to measure the change in the CSA after acromioplasty. Materials and methods Ninety patients were included in this retrospective series. The CSA and the type of acromion were evaluated before and after surgery. Results The average CSA for patients before surgery was 35.9° (± 3.7, 26.2, 44.2) and 33° after the acromioplasty (± 3.5, 24.8, 41.4). The decrease was significant and 2.9° on average (± 2.2, − 2.2, 11.9, p = 0.000). Preoperatively, 58% of patients had a CSA ≥ 35° (n = 52) and 24% postoperatively (n = 22, p = 0.000). Conclusions Standardized anterior acromioplasty allows for a significant decrease in the CSA without lateral resection of the acromion. This study confirms the tight link between the CSA and the anterior acromion as well as the interest of this angle to quantify acromioplasty whether anterior or lateral. Level of evidence Level IV, Case Series, Retrospective design.