Hoffa fractures are associated with concomitant soft tissue injures and a high postoperative complication rate

INTRODUCTION

Hoffa fractures are a rare and often overlooked entity. The main goal of surgical treatment is to restore the articular surface and maintain knee function. However, current clinical data indicate heterogeneous outcomes. The aim of this multicenter study was to obtain a representative data set of patients with isolated Hoffa fractures with special emphasis on concomitant soft tissue injuries, diagnostic algorithms, treatment strategies and functional outcomes.

MATERIALS AND METHODS

Participating Level I trauma centres were asked to review their internal database for isolated Hoffa fractures treated surgically between 2010 and 2020. Demographics, mechanism of injury, diagnostic and therapeutic algorithm, Letenneur classification, concomitant soft tissue injuries, and postoperative knee function and complications were analysed.

RESULTS

A total of 56 patients from six participating trauma centres were included. The median age at injury was 45 years (15-94) with a median follow-up of 19 months (2-108). The most common mechanism of injury was high-energy trauma, with unicondylar lateral Letenneur type I and II fractures being the most common. Surgical treatment was independent of the type of fracture and included isolated screw fixation, combined plate and screw fixation and isolated plate osteosynthesis. Isolated screw fixation resulted in significantly better range of motion (ROM) values (p = 0.032), but the highest number of postoperative complications (n = 14/20, n.s.) compared to the other fixation techniques. The highest number of fixation failures requiring revision was observed in the plate and screw fixation group (n = 3/8, p = 0.008). Osteochondral flake fractures (n = 12/43, 27%) and lateral meniscus injuries (n = 5/49, 10%) were commonly seen in Hoffa fractures.

CONCLUSIONS

Treatment of Hoffa fractures with screw fixation resulted in significantly better functional outcomes, probably due to less comminuted fractures. Concomitant cartilage, meniscal and ligamentous injuries are common and warrant preoperative recognition and management.

2-year results of middle-aged patients with two-compartment cartilage lesions in one knee treated with two patient specific metal implants

PURPOSE

Focal chondral lesions of the femur are currently treated with biological repair or arthroplasty. However, some patients are not suitable for either one due to lesion size, age, or prior biological treatment attempts. While singular patient-specific focal mini metal implants already showed good results, the outcomes of bicompartmental implantation of these implants have not been discussed in the literature yet. This study aims to evaluate clinical outcomes of patients who underwent bicompartmental implantation of two patient-specific implants.

METHODS

This prospective, non-randomized, non-comparative pilot study evaluates results up to two years after bicompartmental implantation of two implants (Episealer Implant, Episurf, Stockholm, Sweden). A damage report is compiled using a special MRI program and patient specific implants are manufactured, including 3D-printed surgical instruments to provide exact placement of the implant. The patients were assessed repeatedly using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Visual Analogue Scale (VAS) for pain during the follow-up.

RESULTS

The scores were evaluated three, 12, and 24 months after surgery and showed good results. The median in both scores improved from 37.7 for the KOOS5 preoperatively to 69.1 after 24 months and from 69 for the VAS for pain preoperatively to 9 after 24 months.

CONCLUSION

Overall, for the small study group presented, the early results are promising. With noticeable improvement in KOOS and VAS for pain after two years, patient specific implants appear to become relevant in future standardized treatment of femoral chondral lesions. Especially with bicompartmental implantation, full arthroplasty can be delayed even further.

LEVEL OF EVIDENCE

IV.

S2k Guideline for Tibial Plateau Fractures - Classification, Diagnosis, and Treatment

Tibial plateau fractures are mostly complex and surgically demanding joint fractures, which require a comprehensive understanding of the fracture morphology, ligamentous and neurovascular injuries, as well as the diagnostic and therapeutic options for an optimal clinical outcome. Therefore, a standardised and structured approach is required. The success of the treatment of tibial plateau fractures relies on the interdisciplinary cooperation between surgical and conservative physicians in an outpatient and inpatient setting, physical therapists, patients and service providers (health insurance companies, statutory accident insurance, pension providers). On behalf of the German Society for Orthopaedics and Trauma Surgery (DGOU), the German Trauma Society (DGU) and the Society for Arthroscopy and Joint Surgery (AGA), under the leadership of the Fracture Committee of the German Knee Society (DKG), a guideline for tibial plateau fractures was created, which was developed in several voting rounds as part of a Delphi process. Based on the current literature, this guideline is intended to make clear recommendations and outline the most important treatment steps in diagnostics, therapy and follow-up treatment. Additionally, 25 statements were revised by the authors in several survey rounds using the Likert scale in order to reach a final consensus.

High degree of consensus amongst an expert panel regarding focal resurfacing of chondral and osteochondral lesions of the femur with mini-implants

INTRODUCTION

The rationale for the use of mini-implants for partial resurfacing in the treatment of femoral chondral and osteochondral lesions is still under debate. The evidence supporting best practise guidelines is based on studies with low-level evidence. A consensus group of experts was convened to collaboratively advance towards consensus opinions regarding the best available evidence. The purpose of this article is to report the resulting consensus statements.

METHODS

Twenty-five experts participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted via an online survey of two rounds, for initial agreement and comments on the proposed statements. An in-person meeting between the panellists was organised during the 2022 ESSKA congress to further discuss and debate each of the statements. A final agreement was made via a final online survey a few days later. The strength of consensus was characterised as: consensus, 51-74% agreement; strong consensus, 75-99% agreement; unanimous, 100% agreement.

RESULTS

Statements were developed in the fields of patient assessment and indications, surgical considerations and postoperative care. Between the 25 statements that were discussed by this working group, 18 achieved unanimous, whilst 7 strong consensus.

CONCLUSION

The consensus statements, derived from experts in the field, represent guidelines to assist clinicians in decision-making for the appropriate use of mini-implants for partial resurfacing in the treatment of femoral chondral and osteochondral lesions.

LEVEL OF EVIDENCE

Level V.

Comparable Instrumented Knee Joint Laxity and Patient-Reported Outcomes After ACL Repair With Dynamic Intraligamentary Stabilization or ACL Reconstruction: 5-Year Results of a Randomized Controlled Trial

BACKGROUND

Technical innovation has led to the renaissance of anterior cruciate ligament (ACL) repair in the past decade.

PURPOSE/HYPOTHESIS

The present study aimed to compare instrumented knee joint laxity and patient-reported outcomes (PROs) after ACL repair with those after primary ACL reconstruction for acute isolated ACL tears. It was hypothesized that ACL repair would lead to comparable knee joint stability and PROs at 5 years postoperatively in comparison with ACL reconstruction.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 85 patients with acute ACL tears were randomized to undergo either ACL repair using dynamic intraligamentary stabilization (DIS) or primary ACL reconstruction with a semitendinosus tendon autograft. The primary outcome was the side-to-side difference in anterior tibial translation (ΔATT) assessed by Rolimeter testing at 5 years postoperatively. Follow-up examinations were performed at 1, 2, and 5 years. PROs were assessed using the Tegner activity scale, the International Knee Documentation Committee (IKDC) subjective score, and the Lysholm score. Furthermore, the rates of recurrent instability, other complications, and revision surgery were recorded. A power analysis was performed a priori, and the Friedman test, Mann-Whitney U test, and Bonferroni correction were applied for statistical comparisons with significance set at P < .05.

RESULTS

The mean age at inclusion was 28.3 ± 11.5 years in the ACL repair group and 27.1 ± 11.5 years in the ACL reconstruction group. At 5 years postoperatively, a total of 64 patients (ACL repair: n = 34 of 43 [79%]; ACL reconstruction: n = 30 of 42 [71%]) were available for follow-up. At 5 years, ΔATT was 1.7 ± 1.6 mm in the ACL repair group and 1.4 ± 1.3 mm in the ACL reconstruction group (P = .334). Preinjury PROs were restored as soon as 1 year after surgery and plateaued until 2 and 5 years postoperatively in both groups. At the 5-year follow-up, the mean Lysholm score was 97.0 ± 5.4 versus 94.5 ± 5.5 (P = .322), respectively, and the mean IKDC subjective score was 94.1 ± 9.9 versus 89.9 ± 7.8 (P = .047), respectively, in the ACL repair group versus ACL reconstruction group. At 5 years postoperatively, 12 patients in the ACL repair group (35%; age <25 years: n = 10/12; Tegner score ≥7: n = 10/12) had recurrent instability, of whom 10 underwent single-stage revision ACL reconstruction. In the ACL reconstruction group, there were 6 patients with recurrent instability (20%; age <25 years: n = 6/6; Tegner score ≥7: n = 5/6); however, in 5 patients, staged revision was required. Differences between both groups regarding recurrent instability (P = .09) or ACL revision surgery (P = .118) were not statistically significant. Recurrent instability was associated with age <25 years and Tegner score >7 in both groups.

CONCLUSION

At 5 years after ACL repair with DIS, instrumented knee joint laxity and PROs were comparable with those after ACL reconstruction. Although no significant difference was found between repair and reconstruction, a critical appraisal of the rates of recurrent instability (35% vs 20%, respectively) and revision surgery (38% vs 27%, respectively) is needed. Young age and a high preinjury activity level were the main risk factors for recurrent instability in both groups. However, single-stage revision ACL reconstruction was possible in each case in the ACL repair group. Although ACL reconstruction remains the gold standard in the treatment of ACL tears, the present study supports the use of ACL repair with DIS as a feasible option to treat acute ACL tears in patients aged ≥25 years with low to moderate activity levels (Tegner score <7).

REGISTRATION

DRKS00015466 (German Clinical Trials Register).

A lateral fracture step-off of 2mm increases intra-articular pressure following tibial plateau fracture

INTRODUCTION

The aim of this study was to evaluate the effects of increasing posttraumatic step-offs after lateral tibial plateau fracture reduction on the intra-articular pressure.

MATERIALS AND METHODS

In eight fresh-frozen human cadaveric knees with intact menisci, a standardized sagittal osteotomy of the lateral tibial condyle was performed as an OTA/AO type 41-B1 fracture-model. The fragment was fixed by a customized sled including an angular stable tibia plate to evaluate step-offs from 0 mm to 8 mm in 1mm increments. In a servo-hydraulic testing machine, an axial force was applied to the tibial plateau in 0° (700N), 15° (700N), 30° (700N), 60° (350N), and 90 ° (350N) of flexion while the joint pressure was recorded by two pressure sensors.

RESULTS

A 1mm step-off did not result in an increased joint pressure. At 60° of flexion a 2mm step-off increased the lateral joint pressure by 61.84kPa (P = 0.0027). In 30° of flexion, a 3mm step raised the lateral joint pressure by 66.80kPa (p = 0.0017), whereas in 0°, 15° and 90° of flexion, a 4mm step increased the pressure by >50kPa (P < 0.05). Concomitant medial joint pressure increments were lower than those in the lateral plateau. A significant increase of 19-24kPa in the medial joint pressure was detected in 90° of flexion with a 1mm lateral step (P = 0.0075), in 15° and 60° of flexion with a 2mm step (P < 0.05), in 0° of flexion with a 4mm step (P = 0.0215) and in 30° of flexion with a 7mm step (P = 0.0487).

CONCLUSION

Lateral fracture step-offs of 2mm or larger should be reduced intraoperatively to avoid large increases in lateral joint pressure.

LOQTEQ® VA Periprosthetic Plate-A New Concept for Bicortical Screw Fixation in Periprosthetic Fractures: A Technical Note

Internal fixation using angle stable plates is the treatment standard in periprosthetic fractures around stable implants. To provide instant postoperative full weight-bearing, bicortical screw fixation is advisable but often surgically demanding. This work presents the first clinical results of the LOQTEQ^® VA Periprosthetic Plate (aap Implantate AG, Berlin, Germany), a new plate system to simplify screw placement around implants. This plate system uses insertable hinges that allow for variable angle screw anchorage. Data of 26 patients with a mean age of 80 years and a mean follow-up of 13.9 months were retrospectively collected. Patients were clinically and radiologically examined. Bony union was achieved in 14 out of 15 patients with no signs of non-union or implant loosening. One patient, however, presented with implant failure. Clinical scores demonstrated acceptable results. Since the hinge plates are easy to apply, the first results are promising.

Primary stability of single-stage revision reconstruction of the anterior cruciate ligament in case of failure of dynamic intraligamentary stabilization depends on implant position during ACL repair

INTRODUCTION

The object of this study was to evaluate the primary stability of tibial interference screw (IFS) fixation in single-stage revision surgery of the anterior cruciate ligament (ACL) in the case of recurrent instability after ACL repair with dynamic intraligamentary stabilization (DIS), dependent on the implant position during DIS.

MATERIALS AND METHODS

Tibial aperture fixation in ACL reconstruction (ACL-R) was performed in a porcine knee model using an IFS. Native ACL-R was performed in the control group (n = 15). In the intervention groups DIS and subsequent implant removal were performed prior to single-stage revision ACL-R. A distance of 20 mm in group R-DIS1 (n = 15) and 5 mm in group R-DIS2 (n = 15) was left between the joint line and the implant during DIS. Specimens were mounted in a material-testing machine and load-to-failure was applied in a worst-case-scenario.

RESULTS

Load to failure was 454 ± 111 N in the R-DIS1 group, 154 ± 71 N in the R-DIS2 group and 405 ± 105 N in the primary ACL-R group. Load-to-failure, stiffness and elongation of the group R-DIS2 were significantly inferior in comparison to R-DIS1 and ACL-R respectively (p < 0.001). No significant difference was found between load-to-failure, stiffness and elongation of R-DIS1 and the control group.

CONCLUSION

Primary stability of tibial aperture fixation in single-stage revision ACL-R in case of recurrent instability after DIS depends on monobloc position during ACL repair. Primary stability is comparable to aperture fixation in primary ACL-R, if a bone stock of 20 mm is left between the monobloc and the tibial joint line during the initial procedure.

Patient-specific metal implants for focal chondral and osteochondral lesions in the knee; excellent clinical results at 2 years

PURPOSE

Surgical treatment options for the management of focal chondral and osteochondral lesions in the knee include biological solutions and focal metal implants. A treatment gap exists for patients with lesions not suitable for arthroplasty or biologic repair or who have failed prior cartilage repair surgery. This study reports on the early clinical and functional outcomes in patients undergoing treatment with an individualised mini-metal implant for an isolated focal chondral defect in the knee.

METHODS

Open-label, multicentre, non-randomised, non-comparative retrospective observational analysis of prospectively collected clinical data in a consecutive series of 80 patients undergoing knee reconstruction with the Episealer® implant. Knee injury and Osteoarthritis Outcome Score (KOOS) and VAS scores, were recorded preoperatively and at 3 months, 1 year, and 2 years postoperatively.

RESULTS

Seventy-five patients were evaluated at a minimum 24 months following implantation. Two patients had undergone revision (2.5%), 1 declined participation, and 2 had not completed the full data requirements, leaving 75 of the 80 with complete data for analysis. All 5 KOOS domain mean scores were significantly improved at 1 and 2 years (p < 0.001-0.002). Mean preoperative aggregated KOOS4 of 35 (95% CI 33.5-37.5) improved to 57 (95% CI 54.5-60.2) and 59 (95% CI 55.7-61.6) at 12 and 24 months respectively (p < 0.05). Mean VAS score improved from 63 (95% CI 56.0-68.1) preoperatively to 32 (95% CI 24.4-38.3) at 24 months. The improvement exceeded the minimal clinically important difference (MCID) and this improvement was maintained over time. Location of defect and history of previous cartilage repair did not significantly affect the outcome (p > 0.05).

CONCLUSION

The study suggests that at 2 years, Episealer® implants are safe with a low failure rate of 2.5% and result in clinically significant improvement. Individualised mini-metal implants with appropriate accurate guides for implantation appear to have a place in the management of focal femoral chondral and osteochondral defects in the knee.

LEVEL OF EVIDENCE

IV.

[Current treatment standard for patella fractures in Germany]

BACKGROUND

The treatment of patella fractures is technically demanding. Although the radiological results are mostly satisfactory, this often does not correspond to the subjective assessment of the patients. The classical treatment with tension band wiring with K‑wires has several complications. Fixed-angle plate osteosynthesis seems to be biomechanically advantageous.

OBJECTIVE

Who is treating patella fractures in Germany? What is the current standard of treatment? Have modern forms of osteosynthesis become established? What are the most important complications?

MATERIAL AND METHODS

The members of the German Society for Orthopedics and Trauma Surgery and the German Knee Society were asked to participate in an online survey.

RESULTS

A total of 511 completed questionnaires were evaluated. Most of the respondents are specialized in trauma surgery (51.5%), have many years of professional experience and work in trauma centers. Of the surgeons 50% treat ≤5 patella fractures annually. In almost 40% of the cases preoperative imaging is supplemented by computed tomography. The classical tension band wiring with K‑wires is still the preferred form of osteosynthesis for all types of fractures (transverse fractures 52%, comminuted fractures 40%). In the case of comminuted fractures 30% of the surgeons choose fixed-angle plate osteosynthesis. If the inferior pole is involved a McLaughlin cerclage is used for additional protection in 60% of the cases.

DISCUSSION

The standard of care for patella fractures in Germany largely corresponds to the updated S2e guidelines. Tension band wiring is still the treatment of choice. Further (long-term) clinical studies are needed to verify the advantages of fixed-angle plates.

Repair With Dynamic Intraligamentary Stabilization Versus Primary Reconstruction of Acute Anterior Cruciate Ligament Tears: 2-Year Results From a Prospective Randomized Study

BACKGROUND

Anterior cruciate ligament (ACL) repair has once again become a focus of research because of the development of new techniques.

PURPOSE/HYPOTHESIS

The purpose was to compare the functional results and recurrent instability rates in patients undergoing ACL repair with dynamic intraligamentary stabilization (DIS) versus primary ACL reconstruction (ACLR) for acute isolated ACL tears. The hypothesis was that functional results and knee joint stability after ACL repair with DIS would be comparable with that after ACLR.

STUDY DESIGN

Randomized clinical trial; Level of evidence, 1.

METHODS

A total of 85 patients with acute ACL tears were randomized to undergo either ACL repair with DIS or primary ACLR. The preinjury activity level and function were recorded. Follow-up examinations were performed at 6 weeks and 6, 12, and 24 months postoperatively. Anterior tibial translation (ATT) was evaluated using Rolimeter testing. The Tegner activity scale, International Knee Documentation Committee (IKDC) subjective form, and Lysholm knee scoring scale scores were obtained. Clinical failure was defined as ΔATT >3 mm in combination with subjective instability. Recurrent instability and other complications were recorded.

RESULTS

There were 83 patients (97.6%) who were successfully followed until 2 years. ATT was significantly increased in the DIS group compared with the ACLR group (ΔATT, 1.9 vs 0.9 mm, respectively; P = .0086). A total of 7 patients (16.3%) in the DIS group had clinical failure and underwent single-stage revision. In the ACLR group, 5 patients (12.5%) had failure of the reconstruction procedure; 4 of these patients required 2-stage revision. The difference in the failure rate was not significant (P = .432). There were 4 patients (3 in the DIS group and 1 in the ACLR group) who showed increased laxity (ΔATT >3 mm) without subjective instability and did not require revision. Recurrent instability was associated with young age (<25 years) and high Tegner scores (>6) in both groups. No significant differences between ACL repair with DIS and ACLR were found for the Tegner, IKDC, and Lysholm scores at any time.

CONCLUSION

Whereas ATT measured by Rolimeter testing was significantly increased after ACL repair with DIS, clinical failure was similar to that after ACLR. In addition, functional results after ACL repair with DIS for acute tears were comparable with those after ACLR. The current study supports the use of ACL repair with DIS as an option to treat acute ACL tears.

REGISTRATION

DRKS00015466 (German Clinical Trials Register).

Implant preloading in extension reduces spring length change in dynamic intraligamentary stabilization: a biomechanical study on passive kinematics of the knee

PURPOSE

Dynamic intraligamentary stabilization (DIS) is a primary repair technique for acute anterior cruciate ligament (ACL) tears. For internal bracing of the sutured ACL, a metal spring with 8 mm maximum length change is preloaded with 60-80 N and fixed to a high-strength polyethylene braid. The bulky tibial hardware results in bone loss and may cause local discomfort with the necessity of hardware removal. The technique has been previously investigated biomechanically; however, the amount of spring shortening during movement of the knee joint is unknown. Spring shortening is a crucial measure, because it defines the necessary dimensions of the spring and, therefore, the overall size of the implant.

METHODS

Seven Thiel-fixated human cadaveric knee joints were subjected to passive range of motion (flexion/extension, internal/external rotation in 90° flexion, and varus/valgus stress in 0° and 20° flexion) and stability tests (Lachman/KT-1000 testing in 0°, 15°, 30°, 60°, and 90° flexion) in the ACL-intact, ACL-transected, and DIS-repaired state. Kinematic data of femur, tibia, and implant spring were recorded with an optical measurement system (Optotrak) and the positions of the bone tunnels were assessed by computed tomography. Length change of bone tunnel distance as a surrogate for spring shortening was then computed from kinematic data. Tunnel positioning in a circular zone with r = 5 mm was simulated to account for surgical precision and its influence on length change was assessed.

RESULTS

Over all range of motion and stability tests, spring shortening was highest (5.0 ± 0.2 mm) during varus stress in 0° knee flexion. During flexion/extension, spring shortening was always highest in full extension (3.8 ± 0.3 mm) for all specimens and all simulations of bone tunnels. Tunnel distance shortening was highest (0.15 mm/°) for posterior femoral and posterior tibial tunnel positioning and lowest (0.03 mm/°) for anterior femoral and anterior tibial tunnel positioning.

CONCLUSION

During passive flexion/extension, the highest spring shortening was consistently measured in full extension with a continuous decrease towards flexion. If preloading of the spring is performed in extension, the spring can be downsized to incorporate a maximum length change of 5 mm resulting in a smaller implant with less bone sacrifice and, therefore, improved conditions in case of revision surgery.

Changes in gait pattern and early functional results after ACL repair are comparable to those of ACL reconstruction

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.

Reverse total shoulder arthroplasty for type I fracture sequelae after internal fixation of proximal humerus fractures

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.

Cost-utility analysis of dynamic intraligamentary stabilization versus early reconstruction after rupture of the anterior cruciate ligament

OBJECTIVES

The aim of this study was to evaluate the cost-effectiveness of the dynamic intraligamentary stabilization (DIS) technique in comparison with reconstructive surgery (ACLR) in the treatment of isolated anterior cruciate ligament (ACL) ruptures from the perspective of the community of insured citizens in Germany.

METHODS

Because of the specific decision problem at hand, namely that with DIS the procedure has to take place within 21 days after the initial trauma, a decision tree was developed. The time horizon of the model was set to 3 years. Input data was taken from official tariffs, payer data, the literature and assumptions based on expert opinion when necessary.

RESULTS

The decision tree analysis identified the DIS strategy as the superior one with 2.34 QALY versus 2.26 QALY for the ACLR branch. The higher QALY also came with higher costs of 5,398.05 € for the DIS branch versus 4,632.68 € for the ACLR branch respectively, leading to an ICER of 9,092.66 € per QALY. Results were robust after sensitivity analysis. Uncertainty was examined via probabilistic sensitivity analysis resulting in a slightly higher ICER of 9,567.13 € per QALY gained.

CONCLUSION

The DIS technology delivers an effective treatment for the ACL rupture at a favorable incremental cost-effectiveness ratio.

Knee joint kinematics after dynamic intraligamentary stabilization: cadaveric study on a novel anterior cruciate ligament repair technique

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.

Influence of Different Tibial Fixation Techniques on Initial Stability in Single-Stage Anterior Cruciate Ligament Revision With Confluent Tibial Tunnels: A Biomechanical Laboratory Study

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.

Biomechanical evaluation of different surgical techniques for treating patellar tendon ruptures

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.

Treatment of proximal humerus fractures with a CFR-PEEK plate: 2-year results of a prospective study and comparison to fixation with a conventional locking plate

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.

The Müller acetabular reinforcement ring--still an option in acetabular revision of Paprosky 2 defects? Longterm results after 10 years

BACKGROUND

Aim of this study was to measure the clinical and radiological longterm outcome after acetabular revision arthroplasty (RTHA) using the Müller acetabular reinforcement ring.

MATERIAL AND METHODS

86 patients with 90 revision arthroplasties and a mean age of 68 years (41 to 84) were included. The mean follow-up was 10 years (range 7-12). The Harris Hip Score and the WOMAC Index were used to assess pain and functional outcome. Furthermore clinical examination of range of motion and radiologic examinations were performed in 34 patients.

RESULTS

The radiologic analysis reports no signs of loosening in 79%, 15% showed possibly loosening and 6% probable loosening. Definite radiologic loosening has not been detected. In the meantime 12 patients (13.3%) of 90 revision total hip arthroplasty underwent a revision of the acetabulum with change of the acetabular component which means a survival rate of 86.7% after 10 years follow-up. The mean center of rotation of the hip moved 0.15 cm (SD 0.74 cm) laterally and 0.1 cm (SD 0.97 cm) cranially based on the geometrically reconstructed center of rotation. A mean score of 58 points for the Harris Hip Score (range 14-93) indicated a poor functional outcome, while a mean value of 96 points (range 0-223) for the WOMAC Index indicated good results for functional outcome in daily living.

CONCLUSIONS

The revision arthroplasty in cases with acetabular defects using the Müller acetabular reinforcement ring shows acceptable longterm results.

LEVEL OF EVIDENCE

Level IV.

Utilisation of Blood Components in Trauma Surgery: A Single-Centre, Retrospective Analysis before and after the Implementation of an Educative PBM Initiative

BACKGROUND

The aim of our single-centre retrospective study presented here is to further analyse the utilisation of allogeneic blood components within a 5-year observation period (2009-2013) in trauma surgery (15,457 patients) under the measures of an educational patient blood management (PBM) initiative.

METHODS

After the implementation of the PBM initiative in January 2012, the Institute of Transfusion Medicine und Transplantation Immunology educates surgeons and nurses at the Department of Trauma Surgery to avoid unnecessary blood transfusions. A standardised reporting system was used to document the utilisation of blood components carefully for the most frequent diagnoses and surgical interventions in trauma surgery. These measures served as basis for the implementation of an interdisciplinary systematic exchange of information to foster decision-making processes in favour of patient blood management.

RESULTS

Since January 2012, the proportion of patients who received a transfusion as well as the number of transfused red blood cell (RBC) (7.3%/6.4%; p = 0.02), fresh frozen plasma (FFP) (1.7%/1.3%; p < 0.05) and platelet (PLT) (1.0%/0.5%; p < 0.001) units were reduced as a result of our PBM initiative. However, among the transfused patients, the number of administered RBC, FFP and PLT units did not decrease significantly. Overall, patients who did not receive transfusions were younger than transfused patients (p = 0.001). The subgroup with the highest probability of blood transfusion administered included patients with intensive care and long-term ventilation (before/after implementation of PBM: RBC 81.5%/75.9%; FFP 33.3%/20.4%; PLT 24.1%/13.0%). Only a total of 60 patients of 531 patients suffering multiple traumas were massively transfused (before/after implementation of PBM: RBC 55.6%/49.8%; FFP 28.4%/20.4%; PLT 17.6%/8.9%).

CONCLUSION

According to our educational PBM initiative, at least the proportion of trauma patients who received allogeneic blood transfusions could be reduced significantly. However, in case of blood transfusions, the total consumption of RBC, FFP and PLT units remained stable in both time periods. This phenomenon might indicate that the actual need of blood transfusions rather depends on the severity of trauma-related blood loss, the coagulopathy rates or the complexity of the surgical intervention which mainly determines the intra-operative blood loss. Taken together, educational training sessions and systematic reporting systems are suitable measures to avoid unnecessary allogeneic blood transfusions and to continuously improve their restrictive application.

MPFL reconstruction using a quadriceps tendon graft: part 1: biomechanical properties of quadriceps tendon MPFL reconstruction in comparison to the Intact MPFL. A human cadaveric study

BACKGROUND

The aim of this study was to analyze the structural properties of the original MPFL and to compare it to a MPFL-reconstruction-technique using a strip of quadriceps tendon.

METHODS

In 13 human cadaver knees the MPFLs were dissected protecting their insertion at the patellar border. The MPFL was loaded to failure after preconditioning with 10 cycles in a uniaxial testing machine evaluating stiffness, yield load and maximum load to failure. In the second part Quadriceps-MPFL-reconstruction was performed and tested in a uniaxial testing machine. Following preconditioning, the constructs were cyclically loaded 1000 times between 5 and 50 N measuring the maximum elongation. After cyclic testing, the constructs have been loaded to failure measuring stiffness, yield load and maximum load. For statistical analysis a repeated measures (RM) one-way ANOVA for multiple comparisons was used. The significance was set at P<0.05.

RESULTS

During the load to failure tests of the original MPFL the following results were measured: stiffness 29.4 N/mm (+9.8), yield load 167.8 N (+80) and maximum load to failure 190.7 N (+82.8). The results in the QT-technique group were as follows: maximum elongation after 1000 cycles 2.1 mm (+0.8), stiffness 33.6 N/mm (+6.8), yield load 147.1 N (+65.1) and maximum load to failure 205 N (+77.8). There were no significant differences in all tested parameters.

CONCLUSIONS

In a human cadaveric model using a strip of quadriceps-tendon 10 mm wide and 3mm deep, the biomechanical properties match those of the original MPFL when tested as a reconstruction.

CLINICAL RELEVANCE

The tested QT-technique shows sufficient primary stability with comparable biomechanical parameters to the intact MPFL.

Comparing the outcomes between Chopart, Lisfranc and multiple metatarsal shaft fractures

OBJECTIVES

Complex midfoot injuries could lead to severe functional impairment of mobility and quality of daily living. Aim of this study was to compare the clinical and functional outcomes of Chopart, Lisfranc fractures and multiple metatarsal shaft fractures.

DESIGN

Retrospective case series.

SETTING

Level one trauma center.

INTERVENTION

Open or closed reduction and internal fixation with screws, K-wires, plates, external fixation or combination of different technics.

MAIN OUTCOME MEASUREMENTS

The American Orthopaedic Foot and Ankle Society (AOFAS) Midfoot Score and the Maryland Foot Score were used to assess pain and functional outcome. 3D gait analysis, pedobarographic analysis and radiologic examinations were performed. The activity level was measured by a step counting accelerometer. All results were compared to an age-matched healthy control group.

RESULTS

24 patients with a median age of 44 years (16-72) were included: 12 patients with multiple metatarsal shaft fractures, 6 patients with Chopart and 6 patients with Lisfranc fractures. The median follow-up was 2.6 years. The pedobarographic analysis reports reduced contact time of the total foot (p = 0.08), the forefoot (p = 0.008) and the hallux (p = 0.015) for the injured foot. A median score of 64 for the SF-36, 64 for the AOFAS Midfoot Score and 73 for the Maryland Foot Score indicated a poor restoration of foot function. Multiple metatarsal shaft fractures presented a significantly lower walking speed (p = 0.03) and cadence (p = 0.04).

CONCLUSION

The worst results were reported for multiple metatarsal shaft fractures on outcome scores, pedobarography, gait analysis and activity. Metatarsal serial fractures should not be underestimated as well as Chopart and Lisfranc fractures.

LEVEL OF EVIDENCE

Level IV.

Comparison of outside-in and inside-out technique for tibial fixation of a soft-tissue graft in ACL reconstruction using the Shim technique

INTRODUCTION

The aim of this study was to compare the biomechanical properties of tibial fixation of a free tendon graft in ACL reconstruction using the Shim, a new wedge-shaped implant, in an outside-in technique to fixation by the Shim used in an inside-out technique and fixation by interference screw in a porcine model.

MATERIALS AND METHODS

Porcine tibia and flexor tendons were used. In Group 1, the Shim was applied outside-in. In Group 2, the Shim was inserted inside-out. In the Group 3, an 8-mm interference screw was used. Ten specimens were tested in each group. Load-to-failure, elongation, stiffness and failure mode were recorded. Cyclic loading was performed between 5 and 250 N for 1,000 cycles, followed by a load to failure testing.

RESULTS

Mean maximum load-to-failure was 629.53 N in Group 1,648.54 N in Group 2 and 749.53 N in Group 3. There was no significant difference between the groups. Stiffness varied between 127.34 N/mm in Group 1, 151.27 N/mm in Group 2 and 182.25 N/mm in Group 3. No significant differences were found between outside-in Shim and interference screw fixation. No significant difference was found for elongation among the three groups. The main failure mode was a rupture of the tendon in the IFS group and a slippage of either the implant or the tendon in both groups using the Shim.

CONCLUSIONS

As no statistically significant difference could be seen concerning load to failure, stiffness and elongation between the inside-out and the outside-in techniques, the Shim can be used for tibial fixation in an outside-in or inside-out technique depending on the preference of the surgeon. To prevent slippage of the graft a hybrid fixation should be considered.

Combination of a floating clavicle and a posterior shoulder dislocation: An "Unhappy Triad" of the shoulder girdle

We present a case of a 31-year-old man who suffered from a floating clavicle in combination with a reverse Hill-Sachs lesion of his right shoulder girdle after a bicycle accident. Operative treatment was performed using minimal-invasive and arthroscopically assisted techniques. We strongly recommend an early CT scan with later 3-dimensional reconstruction to detect and fully understand these complex injuries.

Comparison of tension band wiring and precontoured locking compression plate fixation in Mayo type IIA olecranon fractures

Aim of the present study was to compare the clinical and radiographic outcome of tension band wiring and precontoured locking compression plate fixation in patients treated surgically for an isolated olecranon fractures type IIA according to the Mayo classification. Of 26 patients presenting with an isolated Mayo type IIA olecranon fracture, 13 underwent fixation with a precontoured locking compression plate (group A), 13 patients were treated with tension band wiring (group B). At a mean follow-up of 43 months, patients were clinically and radiographically re-examined using the DASH score, the Mayo Elbow Performance score (MEPS) and anteroposterior and lateral radiographs. The mean DASH score was 14 points in group A and 12.5 points in group B. Regarding the MEPS, 92% of the patients in group A achieved a good to excellent results in comparison to 77% in group B. No significant differences between the two groups could be detected regarding the clinical and radiographic outcome. Implant-related irritations requiring hardware removal occurred more frequently in group B (12 vs. 7). Procedure and implant related costs were significantly higher in group A. Tension band wiring is still a preferable surgical method to treat simple isolated olecranon fractures. The patient must be informed that in all likelihood implant removal will be required once the fracture has healed. Fixation with precontoured locking compression plates does not provide better functional and radiographic outcome but is more expensive than tension band wiring.

A laboratory investigation to assess the influence of cement augmentation of screw and plate fixation in a simulation of distal femoral fracture of osteoporotic and non-osteoporotic bone

The augmentation of fixation with bone cement is increasingly being used in the treatment of severe osteoporotic fractures. We investigated the influence of bone quality on the mechanics of augmentation of plate fixation in a distal femoral fracture model (AO 33 A3 type). Eight osteoporotic and eight non-osteoporotic femoral models were randomly assigned to either an augmented or a non-augmented group. Fixation was performed using a locking compression plate. In the augmented group additionally 1 ml of bone cement was injected into the screw hole before insertion of the screw. Biomechanical testing was performed in axial sinusoidal loading. Augmentation significantly reduced the cut-out distance in the osteoporotic models by about 67% (non-augmented mean 0.30 mm (sd 0.08) vs augmented 0.13 mm (sd 0.06); p = 0.017). There was no statistical reduction in this distance following augmentation in the non-osteoporotic models (non-augmented mean 0.15 mm (sd 0.02) vs augmented 0.15 mm (sd 0.07); p = 0.915). In the osteoporotic models, augmentation significantly increased stability (p = 0.017).

Feasibility study on the potential of a spiral blade in osteoporotic distal femur fracture fixation

INTRODUCTION

Osteoporotic fractures of the distal femur (primary as well as periprosthetic) are a growing problem in today's trauma and orthopaedic surgery. Therefore, this feasibility study should identify the biomechanical potential of a (commercially available) spiral blade in the distal femur as compared to a single screw without any additional plate fixation. Additionally, the influence of cement augmentation was investigated.

MATERIALS AND METHODS

An artificial low density bone model was either instrumented with a perforated spiral blade or a 5 mm locking screw only. Additionally, the influence of 1 ml cement augmentation was investigated. All specimens were tested with static pull-out and cyclic loading (50 to 250 N with an increment of 0.1 N/cycle).

RESULTS

In the non-augmented groups, the mean pull-out force was significantly higher for the blade fixation (p < 0.001). In the augmented groups, the difference was statistically not significant (p = 0.217). Augmentation could increase pull-out force significantly by 72 % for the blade and 156 % for the screw, respectively (p = 0.001). The mean number of cycles to failure in the non-augmented groups was 12,433 (SD 465) for the blade and 2,949 (SD 215) for the screw, respectively (p < 0.001). In the augmented group, the blade reached 13,967 (SD 1,407) cycles until failure and the screw reached 4,413 (SD 1,598), respectively (p < 0.001).

CONCLUSION

The investigated spiral blade was mechanically superior, significantly, as compared to a screw in the distal femur. These results back up the further development of a distal femoral blade with spiral blade fixation for the treatment of osteoporotic distal femur fractures.

[Treatment of periprosthetic and peri-implant fractures : modern plate osteosynthesis procedures]

Periprosthetic fractures are increasing not only due to the demographic development with high life expectancy, the increase in osteoporosis and increased prosthesis implantation but also due to increased activity of the elderly population. The therapeutic algorithms are manifold but general valid rules for severe fractures are not available. The most commonly occurring periprosthetic fractures are proximal and distal femoral fractures but in the clinical routine fractures of the tibial head, ankle, shoulder, elbow and on the borders to other implants (peri-implant fractures) and complex interprosthetic fractures are being seen increasingly more. It is to be expected that in the mid-term further options, such as cement augmentation of cannulated polyaxial locking screws will extend the portfolio of implants for treatment of periprosthetic fractures. The aim of this review article is to present the new procedures for osteosynthesis of periprosthetic fractures.

Biomechanics of a new technique for minimal-invasive coracoclavicular ligament reconstruction

PURPOSE

To evaluate the biomechanical properties of a new coracoclavicular (CC) ligament reconstruction using a subcoracoidal flip button and a tendon graft compared to an augmented tendon loop and a synthetic coracoclavicular ligament reconstruction.

METHODS

A porcine metatarsalia model was used to assess supero-inferior fixation strength of (1) a new technique using an augmented tendon graft and a subcoracoidal flip button in a lifting block fashion, (2) an augmented tendon loop around the coracoid base and (3) a synthetic coracoclavicular ligament augmentation technique. Cyclic loading from 20 to 70 N for 1,000 cycles was performed, followed by a load-to-failure protocol.

RESULTS

All specimens of the three different groups survived the cyclic loading protocol. The maximum loads to failure under superior loading conditions were 760 ± 78 N for group 1, 702 ± 48 N for group 2 and 1117 ± 91 N for group 3. The synthetic coracoclavicular ligament augmentation technique revealed significantly higher maximum loads compared to the other groups (p < 0.001). The augmented tendon graft/flip button construct had higher maximum loads than the augmented tendon loop (n.s.). No significant differences were found for stiffness and elongation behaviour among the 3 tested groups.

CONCLUSION

The results suggest that the described technique is an alternative option to reconstruct the CC ligaments in AC joint instability in a minimal-invasive technique. Under superior loading conditions, the biomechanical properties exhibited by this novel technique were comparable to those of the tendon loop around the coracoid base.

[Nonunion of the femoral neck and artificial heart. How far may we go?]

Due to medical improvements surgeons are increasingly confronted with conditions associated with severe medical comorbidities. Fracture or nonunion of the femoral neck would have been classified as "inoperable" in the past. We report the successful operative treatment of a patient with femoral neck nonunion after screw osteosynthesis and associated existence of a left ventricular assist device for dilated cardiomyopathy.

Surgical separation of conjoined (Siamese) xiphopagus twins

Conjoined twins of the xiphopagus type have been separated 24 hours after spontaneous delivery. Indication for early intervention was impending rupture of a large omphalocele as well as deterioration of one severely malformed twin who did not survive surgery, whereas the other one showed normal development up to 15 months after separation.