Intraoperative pneumatic tourniquet application reduces soft-tissue microcirculation, but without affecting wound healing in calcaneal fractures.

BACKGROUND: Wound healing complications are a major challenge following the extended lateral approach in calcaneal fractures. Soft-tissue microcirculation plays an important role via the delivery of oxygen, nutrients, and the regulation of a local milieu. The aim of this clinical study was to examine the effect of intraoperative pneumatic tourniquet application on skin and subcutaneous microcirculation, and its impact on wound healing progression. METHODS: Patients with calcaneal fractures were randomly assigned to two groups defined by a surgery conducted either with use or without use of a tourniquet. Blood flow (BF [AU]), tissue oxygen saturation (SO2[%]) and the relative amount of haemoglobin (rHb[AU]) were intraoperatively measured at two depths (2 and 8 mm) non-invasively by spectrophotometry (Micro-Lightguide O2C®, LEA Medizintechnik, Giessen, Germany). Time points were before and after inflation of the pneumatic tourniquet and also at the end of surgery before deflation. A linear mixed model (LMM) was fitted for statistical analysis. RESULTS: Thirty-four patients (3 women and 31 men) with 37 calcaneal fractures were included. In 22 of them, the surgery was conducted with a tourniquet and in the other 15 without its use. A significant decrease of microcirculation, characterized by decreases in blood flow (p = 0.011) and tissue oxygenation (p = 0.023) was measured in 8 mm depth after inflating the tourniquet. However, these changes did not influence the time of postoperative wound healing. CONCLUSION: The use of a pneumatic tourniquet reduces deep microcirculation without affecting postoperative wound healing. Trial registration The study was registered in www. CLINICALTRIALS: gov (NCT01264146).

Lapidus Arthrodesis for Correction of Hallux Valgus Deformity: A Systematic Review and Meta-Analysis.

BACKGROUND: The aim of this study was to evaluate and compare different fixation methods to achieve Tarsometatarsal joint I (TMT-1) arthrodesis in patients with hallux valgus regarding radiographic correction, complication profile, and clinical outcomes. METHODS: A systematic review and meta-analysis included primary literature results of evidence level 1 to 3 studies in German and English. Inclusion and exclusion criteria were established and applied, along with parameters suitable for comparison of data. RESULTS: 16 studies with a total of 1176 participants met the inclusion criteria for this analysis. Twelve evaluation criteria were compared among 3 fixation techniques; comprised of a screw-only, dorsomedial plating- and plantar plating cohort. There was no statistical difference in deformity correction (both intermetatarsal- and hallux valgus angle), or AOFAS score between the cohorts. The complication rate was 13% in the plantar-, 19.5% in the dorsomedial-, and 24.5% in the screw cohort. Nonunion was seen in 0.7% of participants in the plantar, 1.4% in the dorsomedial, and 5.3% in the screw group. The time until complete weightbearing correlated positively with the development of nonunion, with a coefficient of 0.376 (P = .009). Hardware removal was performed in 11.8% of patients in the dorsomedial cohort, 7.7% in the screw cohort, and 3.6% in the plantar cohort. CONCLUSION: Based on the results of meta-analysis of heterogeneous studies, plantar plating facilitated early weightbearing and patient mobilization compared to the other fixation methods, while carrying the lowest nonunion, hardware removal, and general complication risk. However, owing to the relatively small number of patients in the plantar plating group, more work is necessary to elucidate the benefits of plantar plating for a first tarsometatarsal joint arthrodesis. Development of complications appears to be largely dependent on the fixation model, rather than patient mobilization alone.Level of Evidence: 3.

[Treatment of symptomatic end-stage osteoarthritis of the ankle with anterolateral approach and an anatomical plate]. / Sprunggelenkarthrodese über einen anterolateralen Zugang mit einer anatomischen Platte.

OBJECTIVE: The aim of this paper is to describe the anterolateral approach using an anatomical plate for ankle arthrodesis and to present the first mid-term results with this technique in a high-risk population. INDICATIONS: The indication for arthrodesis of the ankle joint with this described technique is moderate to severe osteoarthritis of the ankle. CONTRAINDICATIONS: In addition to the general contraindications typical of any operation, there is a specific contraindication in cases of active infection of the soft tissues and accompanying osteomyelitis at the ankle. SURGICAL TECHNIQUE: The incision is made along the course of the peroneus tertius muscle. After that, the mobilization of the peroneus superficialis nerve is carried out, followed by the mobilization of the long extensor tendons, especially the extensor digitorum muscle in a medial direction opening the capsule and removal of the residual cartilage on the distal tibia and talus. Subsequently, the subchondral sclerosis is opened, and the implantation of a suitable osteosynthesis material, e.g., an anatomical angle-stable plate, is carried out. Finally, wound closure is performed involving the muscle belly of the extensor digitorum muscle covering the plate. POSTOPERATIVE MANAGEMENT: Immobilization of the ankle for 5-7 days in a dorsal knee-high splint. Retention in a walker after decongestion for another 5 weeks. Increased loading can be done after X­ray/computed tomography (CT) control from the 6th week. RESULTS: In all, 11 patients were observed retrospectively for an average of 14 months. There were no complications. The European Foot and Ankle Society (EFAS) score improved significantly from 3.3 to 17.8 points. All patients were subjectively satisfied with the result and would have the operation again.

Postoperative Management of Osteochondral Lesions of the Ankle: A Survey Among German-Speaking Foot and Ankle Surgeons.

OBJECTIVE: To assess the current treatment of osteochondral lesions of the ankle (OCLA) by German-speaking foot and ankle surgeons, focusing on the management of postoperative care and rehabilitation. DESIGN: A questionnaire was created by a panel of 4 experienced foot and ankle surgeons on behalf of the "Clinical Tissue Regeneration" (CTR) working group of the German Society of Orthopaedics and Trauma Surgery (DGOU), and distributed electronically to members of the CTR, participants of the German Cartilage Registry (Knorpelregister DGOU©), and members of 6 German-speaking orthopedics or sports medicine societies. Results were classified depending on the consensus within the answers (agreement ≥75% "strong tendency," 50%-74% "tendency," 25%-49% "weak tendency," <25% "no tendency"). RESULTS: A total of 60 participants returned the questionnaire. The main results are as follows: regarding the frequency of surgical procedures for OCLA, refixation of the fragment, retrograde drilling, and bone marrow stimulation with or without using a matrix were performed by at least 75% of the surgeons and was considered a strong tendency. There was a strong tendency to stabilize the ankle (76.7%) and perform corrective osteotomies (51.7%). In total, 75.5% and 75% of the surgeons performed bone marrow stimulation with and without using a matrix, respectively. Corrective osteotomy and ankle stabilization were performed in 64.5% and 65.2% cases, respectively. Most participants included published recommendations on postoperative rehabilitation and the return to sports activities in their postoperative management. The main surgical procedures were considered the most critical factor in influencing the postoperative management by 81% of the participants (strong tendency). Adjunct surgical procedures such as corrective osteotomy and stabilization of the ankle were considered important by 67.8% of the respondents (tendency). CONCLUSIONS: The management of OCLA varies among German-speaking foot and ankle surgeons. Therefore, guidelines remain essential to standardize the management of OCLA, to achieve improved and stable results. This survey will assist clinicians and patients with rehabilitation to return to sports after treating the ankle's cartilage injury.

Indications and possible limitations using medio-plantar plate systems in tarsometatarsal 1 fusions - A cadaveric study.

BACKGROUND: The tarsometatarsal 1 arthrodesis is an adequate treatment for moderate to severe hallux valgus deformity and instability of the first ray. Plantar plating arthrodesis has been shown to provide better mechanical stability and fewer postoperative complications than screw fixation or medial plating. The medio-plantar plate is a new plate design for Lapidus arthrodesis. It could combine the biomechanical advantages of the plantar plate and the anatomical overview of a medial plate. However, the implanted material can cause irritation of the tibialis anterior, which in some cases may require removal of the material. The purpose of this study was to examine the possibility of tendon irritation following medio-plantar first tarsometatarsal joint arthrodesis using cadaveric specimens. METHODS: The study involved the simulated surgical procedure of medio-plantar plate arthrodesis on 30 lower extremities. After the plates were fixed, a thorough examination of the feet was conducted to assess any tendon irritation and to determine a recommendation for placement of the medio-plantar plate based on the Olewnik classification. RESULTS: Irritation of the tibialis anterior tendon components with the medio-plantar plate depends mainly on the anatomic norm variant, classified according to Olewnik et al. A medio-plantar plate is particularly recommended in TA tendon Olewnik type 3 and type 5. The positioning of a medio-plantar plate in Olewnik type 1 and type 2 tendons depends on the anatomic fit of the medio-plantar plate and the bony configuration of the TMT 1 joint. A large portion of the TA tendon must be detached, so a different plate design may be preferred in these patients. CONCLUSIONS: TMT 1 arthrodesis with medio-plantar plating of the first tarsometatarsal joint should be performed considering the anatomic TA tendon variations. LEVEL OF EVIDENCE: Level V, Expert Opinion includes Case Reports and Technique Tips.

Biomechanical Comparison of Medio-Plantar and Plantar Plate Fixation for First Tarsometatarsal Joint Arthrodesis.

Plantar plate positioning has been demonstrated as biomechanically superior. However, some operators remain resentful about the morbidity of the surgical approach. To provide improved plate fixation for first tarsometatarsal joint arthrodesis with respect to the tibialis anterior tendon, a medio-plantar plate was developed. The purpose of this biomechanical study was to compare its construct stability to that of a plantar plate construct. Twelve pairs of fresh frozen human specimens were used in a matched pair test. Each pair was fixed with a 4 mm compression screw and either a plantar locking plate or a medio-plantar locking plate. A cantilever beam test was performed in dorsiflexion. Before and after cyclic loading (5000 cycles; 40 N), bending stiffness and relative movements at the joint space were monitored in a quasi-static test including optical motion tracking. Maximum load and bending moment to failure were investigated in a load-to-failure ramp test. The bending stiffness of both groups did not significantly differ before (plantar 49.9 N/mm ± 19.2; medio-plantar 53.9 N/mm ± 25.4, p = 0.43) or after (plantar 24.4 N/mm ± 9.7; medio-plantar 35.3 N/mm ± 22.0, p = 0.08) cyclic loading but decreased significantly in both groups (p < 0.01) after cyclic loading. Relative movement increased significantly during cyclic testing in both groups (p < 0.01) but did not differ significantly between the groups before (p = 0.29) or after (p = 0.16) cyclic loading. Neither load nor bending moment to failure were significantly different (plantar 225 N ± 78, 10.8 Nm; medio-plantar 210 N ± 86, 10.1 Nm, p = 0.61). Both plate constructs provided equivalent construct stability, both being well suited for Lapidus arthrodesis.

Etiology, Classification, Diagnostics, and Conservative Management of Osteochondral Lesions of the Talus. 2023 Recommendations of the Working Group "Clinical Tissue Regeneration" of the German Society of Orthopedics and Traumatology.

METHODS: Peer-reviewed literature was analyzed regarding different topics relevant to osteochondral lesions of the talus (OLTs) treatment. This process concluded with a statement for each topic reflecting the best scientific evidence available for a particular diagnostic or therapeutic concept, including the grade of recommendation. Besides the scientific evidence, all group members rated the statements to identify possible gaps between literature and current clinical practice. CONCLUSION: In patients with minimal symptoms, OLT progression to ankle osteoarthritis is unlikely. Risk factors for progression are the depth of the lesion on MRI, subchondral cyst formation, and the extent of bone marrow edema. Conservative management is the adaptation of activities to the performance of the ankle joint. A follow-up imaging after 12 months helps not to miss any progression. It is impossible to estimate the probability of success of conservative management from initial symptoms and imaging. Cast immobilization is an option in OLTs in children, with a success rate of approximately 50%, although complete healing, estimated from imaging, is rare. In adults, improvement by conservative management ranges between 45% and 59%. Rest and restrictions for sports activities seem to be more successful than immobilization. Intra-articular injections of hyaluronic acid and platelet-rich plasma can improve pain and functional scores for more than 6 months. If 3 months of conservative management does not improve symptoms, surgery can be recommended.

The Correction Potential of the Lateral Release of the Hallux Valgus: A Comparative Anatomical Study of Minimally Invasive Versus Open Surgical Technique Using a Dorsal Approach.

Background: Lateral release (LR) is an integral part of surgical correction of hallux valgus. A comparison was made between the open and minimally invasive LR techniques using a dorsal approach. The reliability and safety of the two methods were compared. Besides, the release of specific structures was investigated with special emphasis on ascertaining if the release was partial or a total one. Methods: In this study on cadavers, LR was performed on nine pairs of foot and ankle specimens. The group assignments were randomized for each case. The operations were followed by anatomical preparation, data collection, photo documentation, and statistical analysis. Results: A statistically significant advantage was observed with the open dorsal approach as there was a complete release of the adductor hallucis muscle from the lateral sesamoid and the lateral metatarsosesamoid ligament (p = 0.015 in each case). In terms of releasing the adductor hallucis muscle from the proximal phalanx, the lateral joint capsule, and the lateral collateral ligament, none of the investigated procedures showed better performance. However, open dorsal access tends to show a higher degree of release more frequently. Conclusions: Splitting of the lateral joint capsule, including the lateral collateral ligament and lateral metatarsosesamoid ligament via the dorsal approach can be performed reliably and completely using the open surgical technique. The open dorsal technique shows better rates of detachment when the adductor hallucis muscle is released from the lateral sesamoid. Both techniques resulted in incomplete release of the adductor hallucis muscle from the proximal phalanx. Study Type: Therapeutic-investigating the results of a treatment. Level of Evidence: II (Prospective cohort study). Supplementary Information: The online version contains supplementary material available at 10.1007/s43465-021-00575-3.

Iatrogenic Damage to Neurovascular and Soft Tissue Structures During Lateral Release of Hallux Valgus: A Comparative Anatomical Study of Minimally Invasive Versus Open Surgical Techniques.

Lateral release is often an integral step in surgical correction of hallux valgus and can be performed using open or minimally invasive techniques. We investigated whether these techniques cause iatrogenic damage to arteries, nerves, tendons, or joint capsules. In this cadaver study, lateral release was performed on 9 pairs of specimens by a specialized foot surgeon. The specimens were randomly assigned to each group. The operations were followed by anatomical preparation, data collection, photo documentation, and statistical analysis. Iatrogenic damage to arteries, nerves, tendons, or joint capsules was rare, regardless of the surgical technique used. However, with the minimally invasive technique, the tendon of the extensor hallucis longus muscle and the sensitive terminal branches of the fibular nerve were at risk due to their anatomical proximity to the access portal. The deep transverse metatarsal ligament was potentially at risk if the adductor hallucis muscle was completely detached from the lateral sesamoid. When the deep transverse metatarsal ligament was transected there was risk of damaging the underlying plantar neurovascular structures. Both surgical techniques are safe in terms of the risk of injury to neighboring neurovascular and soft tissue structures.

Anatomical Study of Sinus Tarsi-Based Lateral Lengthening Calcaneal Osteotomy.

BACKGROUND: Lateral lengthening calcaneal osteotomy (LL-CO) is commonly performed as a treatment for an abducted midfoot in pes planovalgus deformity. The purpose of this study is to investigate potential damage to medial structures with a sinus tarsi LL-CO. METHODS: Sixteen cadaver feet were used. Eight feet had an extended lateral approach, and 8 had a limited lateral (sinus tarsi) approach. All underwent a sinus tarsi LL-CO. Specimens were then dissected to identify inadvertent injury to medial structures. RESULTS: Sinus tarsi LL-CO was associated with damage to the sustentaculum tali and medial articular facets in 56% and 62.5% of specimens, respectively. No anterior or posterior facet injuries were found, although 56% of specimens had a confluent medial and anterior facet. CONCLUSION: Damage to the medial articular facet and sustentaculum is possible with a flat cut sinus tarsi LL-CO due to the curved nature of the relevant sinus tarsi and canal anatomy. CLINICAL RELEVANCE: Sinus tarsi LL-CO needs to be performed with caution since damage to the subtalar joint is possible. LEVEL OF EVIDENCE: Level II, prospective cohort study.

[Description of a technique that uses Lapidus arthrodesis plus osteochondral autotransplantation in the treatment of severe hallux rigidus]. / Lapidusarthrodese in Kombination mit einer osteochondralen Autotransplantation in das Metatarsale-I-Köpfchen zur Behandlung der fortgeschrittenen Arthrose des Großzehengrundgelenkes.

OBJECTIVE: The objective of this technique is the treatment a severe hallux rigidus deformity by reorientation of an elevated first metatarsal using arthrodesis of the first tarsometatarsal joint and performing a one-step transplantation of an osteochondral graft, which is harvested from the first cuneiform, to the head of the first metatarsal bone. INDICATIONS: Severe arthritis of the first metatarsophalangeal joint (MTP) stage 3 and 4 in the Vanore classification. CONTRAINDICATIONS: General contraindications for a foot surgery; ankylosis of MTP joint; severe arthritis of the sesamoid joint; osteonecrosis; short first metatarsal; previous infection in the metatarsophalangeal joint; large cysts at the head of the first metatarsal. SURGICAL TECHNIQUE: The first step is the preparation of the metatarsophalangeal and the first tarsometatarsal joint. After mobilizing the first metatarsal in a medioplantar direction, a cartilage-bone cylinder is removed from the articular surface of the medial cuneiform using special osteochondral autograft transfer system (OATS) instruments (Small Joint OATS, Arthrex medical instruments GmbH, Munich, Germany). This is followed by the arthrodesis of the first tarsometatarsal joint with reorientation of the position of the first metatarsal bone. Then the removed osteochondral cylinder is implanted into the articular surface of the first metatarsal head. After that the capsule is closed and the skin sutured. POSTOPERATIVE MANAGEMENT: Postoperative management is guided mainly by the requirements of the first tarsometatarsal arthrodesis. When a plantar plate is used pain orientated full weightbearing is allowed in a postoperative shoe with a stiffened sole for 6-8 weeks. Physiotherapy is prescribed to exercise the first metatarsophalangeal joint. RESULTS: In the study, 5 patients were treated with the method described in the years 2011-2012 and were followed up for a period of 2 years. All of these patients were subjectively satisfied with the outcome of the operation. There were no relevant surgery-associated complications.

[Cartilage chip transplantation for cartilage defects of the first metatarsophalangeal joint]. / Minced Cartilage bei Knorpeldefekten am Großzehengrundgelenk.

OBJECTIVE: Treatment of circumscribed cartilage defects in the first metatarsophalangeal joint (MTP1) using autologous cartilage fragments. INDICATIONS: Full thickness cartilage defects (ICRS IV) or focal osteoarthritis in combination with hallux rigidus. CONTRAINDICATIONS: Pre-existing ankylosis of the metatarsophalangeal joint; global osteoarthritis of the joint; advanced osteoarthritis of the sesamoidal articulation; osteonecrotic cysts in the head of the first metatarsal bone. SURGICAL TECHNIQUE: Preparation of the metatarsophalangeal joint. Mobilization of the first metatarsal head. Harvesting of the cartilage fragments from the dorsal rim portion as part of the cheilectomy. Mincing the cartilage fragments with a 3.0 mm shaver in sterile conditions. Augmenting the cartilage fragments with autologous conditioned plasma (ACP). Preparing the defect area and creation of a "contained" defect. Replantation of the resulting minced cartilage mass into the defect of the articular surface on the first metatarsal head. POSTOPERATIVE MANAGEMENT: Immobilization of the MTP1 for 48 h. Intensive physiotherapy for 3 months. Full weight bearing after reduced swelling. RESULTS: In 2020, 5 patients were treated with the method described and followed up for a period of 1 year. All patients were subjectively satisfied with the result of the operation. There were no relevant surgery-associated complications.

Reduced pre-operative skin oxygen saturation predicts revision after open reduction and internal fixation in calcaneal fractures : A reduced pre-operative oxygen saturation as measured by laser-Doppler spectrophotometry in 8 mm depth is associated with revision surgery after open reduction and internal fixation of calcaneal fractures through an extended lateral approach.

PURPOSE: To assess which pre-operative parameters correlate with wound revisions after an extended lateral approach to the calcaneus. METHODS: Pre-operative laser-Doppler spectrophotometry was applied in patients undergoing open reduction and internal fixation. The number of wound revisions was recorded during pos-toperative follow-up. Spearman rho analysis was used to identify factors associated with wound revision and receiver operator characteristics curves were calculated for the identified factors. RESULTS: Thirty-four patients (29 men, 5 women; 37 calcanei) with a mean patient age of 43 ± 14 years were analyzed. The minimal oxygen saturation value at the five measurement locations as well as the minimal value for flow correlated negatively with wound revisions (p value = 0.025 and 0.038, respectively). The area under the curve for the pre-operative minimal value of oxygen saturation was 0.841 (95%CI 0.64-1.00, p = 0.028), indicating a good accuracy as a test to predict wound revision. CONCLUSION: A pre-operative oxygen saturation of at least 20.5% across five measurement points along the anticipated incision identified all patients not needing a wound revision (negative predictive value 100%). On the other hand, patients with at least one measurement below 20.5% were at risk for wound revision surgery (sensitivity 100%, specificity 48.5%). ClinicalTrials.gov NCT01264146.

Arthroscopic Minced Cartilage Implantation for Chondral Lesions at the Talus: A Technical Note.

In the past few years, autologous chondrocyte implantation has been shown to be the most suitable cartilage reconstructive technique with the best tissue quality. Although this method is part of the standard surgical repertoire in the knee joint, it has so far not been an established method in the ankle because there are no prospective randomized controlled studies to prove a significant advantage over alternative methods of cartilage repair. The methods most frequently used in this context (e.g., marrow stimulation techniques) can, however, at most generate hyaline-like and thus biomechanically inferior regenerates. Minced cartilage implantation, on the other hand, is a relatively simple and cost-effective 1-step procedure with promising biological potential and-at least in the knee joint-satisfactory clinical results. We present an arthroscopic surgical technique by which the surgeon can apply autologous chondrocytes in a 1-step procedure (AutoCart; Arthrex, Munich, Germany) to treat articular cartilage defects in the ankle joint.

Ligamentous Lisfranc injuries: analysis of CT findings under weightbearing.

PURPOSE: The aim of this study was to investigate the influence of different ligamentous Lisfranc injuries on computed tomography (CT) findings under weight-bearing and to emphasize the indications for surgical treatment of their various types. METHODS: Sixteen human cadaveric lower limbs were placed in weight-bearing radiolucent frame for CT scanning. All intact specimens were initially scanned, and then, dorsal approach was used for sequential ligaments cutting of: (1) the dorsal and the interosseous (Lisfranc) ligaments between medical cuneiform (MC) and metatarsal 2 (MT2); (2) the plantar ligament between the MC and MT3; (3) the plantar ligament between MC and MT2. Based on sequential CT scans, the distances MT1-MT2, MC-T2, as well as the alignment and dorsal displacement of MT2 were measured. RESULTS: Slight increase in the distances MT1-MT2 and MC-MT2 was observed after the disruption of the dorsal and the interosseous ligaments. Further increase in MT1-MT2 and MC-MT2 distances was registered after the disruption of the ligament between MC and MT3. The largest distances MT1-MT2 and MC-MT2 were measured after the final plantar ligament cut between MC and MT2. CONCLUSIONS: Unequivocal instability is observed with simultaneous transection of the Lisfranc ligament with both plantar ligaments. On CT used as diagnostic tool, plantar injuries at the basis of the second and the third metatarsal are indirect signs of violation of the ligaments and represent an indication for surgical treatment. When using magnetic resonance imaging as diagnostic tool, a ruptured Lisfranc ligament alone without dislocation does not necessarily need surgical intervention.

Biomechanical evaluation of retrograde docking nailing to a total hip arthroplasty stem in a periprosthetic femur fracture model.

INTRODUCTION: Slotted nails allow a connection to a total hip arthroplasty (THA) stem and act as intramedullary load carrier. This study compares construct stiffness, cycles to failure and failure load between a retrograde slotted femur nail construct docked to a THA stem and a lateral locking plate in a human periprosthetic femur fracture model. MATERIALS AND METHODS: In seven pairs of fresh-frozen human anatomic femora with cemented THA, a transverse osteotomy was set simulating a Vancouver type B1 fracture. The femora were instrumented pairwise with either a retrograde slotted nail coupled to the prosthesis stem, or a locking plate plus a locking attachment plate. Four-point mediolateral bending, torsional and axial bending construct stiffness was investigated via non-destructive tests. Cyclic testing under progressively increasing physiologic loading was performed at 2 Hz until catastrophic construct failure. RESULTS: Mediolateral bending stiffness did not differ significantly between the two groups (P=0.17) but exhibited a biphasic profile with significantly increased stiffness in both groups (P<0.01). Nail constructs provided a significantly lower torsional stiffness (0.49 ± 0.66 Nm/°) than plate constructs (1.70 ± 0.86 Nm/°), P=0.03. Axial bending stiffness did not differ significantly between the groups (Nail: 605 ± 511 N/mm; Plate: 381 ± 428 N/mm), P=0.61. Cycles to failure and failure load were significantly higher for the plate constructs (25'700 ± 8'341; 3'070 ± 1334 N) compared with the nail constructs (20'729 ± 7'949; 2'573 ± 1295 N), P=0.04. CONCLUSION: The docking nail construct provides an intramedullary fixation with connection to the prosthesis stem; however, it is biomechanically weaker in stable fractures compared to the plate construct.

Biomechanical evaluation of the docking nail concept in periprosthetic fracture fixation around a stemmed total knee arthroplasty.

Intramedullary femoral nails provide an ideal mechanical axis for periprosthetic fracture fixation. Slotted nails allow a connection to a total knee arthroplasty (TKA) stem. This study aims to compare implant and construct stiffness, interfragmentary movement and cycles to failure between an antegrade slotted femoral nail construct docked to a TKA stem and a distal femoral locking plate in a human periprosthetic femoral fracture model. In eight pairs of fresh-frozen human femora with stalked TKA, a 10 mm transverse osteotomy gap was set simulating a Rorabeck type II, Su type I fracture. The femora were pairwise instrumented with either an antegrade slotted nail coupled to the prosthesis stem, or a locking plate. Cyclic testing with a progressively increasing physiologic loading profile was performed at 2 Hz until catastrophic construct failure. Relative movement at the osteotomy site was monitored by means of optical motion tracking. In addition, four-point bending implant stiffness, torsional implant stiffness and frictional fit of the stem-nail connection were investigated via separate non-destructive tests. Intramedullary nails exhibited significantly higher four-point bending and significantly lower torsional implant stiffness than plates, P < 0.01. Increasing difference between nail and stem diameters decreased frictional fit at the stem-nail junction. Nail constructs provided significantly higher initial axial bending stiffness and cycles to failure (200 ± 83 N/mm; 16'871 ± 5'227) compared to plate constructs (93 ± 35 N/mm; 7'562 ± 1'064), P = 0.01. Relative axial translation at osteotomy level after 2'500 cycles was significantly smaller for nail fixation (0.14 ± 0.11 mm) compared with plate fixation (0.99 ± 0.20 mm), P < 0.01. From a biomechanical perspective, the docking nail concept offers higher initial and secondary stability under dynamic axial loading versus plating in TKA periprosthetic fracture fixation.

Lateralising DMMO (MIS) for simultaneous correction of a pes adductus during surgical treatment of a hallux valgus.

The surgical correction of a hallux valgus deformity presenting with a pes adductus has long proven to be a difficult undertaking. The medial shift of the metatarsal bones limits the scope for surgical correction and leads to inherently high reoccurrence rates. Current invasive treatments often give rise to profound soft tissue trauma and prolonged swelling, while requiring strict relief from weight-bearing in the affected foot. In this paper, it is aimed to introduce an easy and useful modification of the Distal Metatarsal Minimal-invasive Osteotomy (DMMO) to perform the effective, simultaneous correction of a pes adductus during surgical treatment of a hallux valgus. We followed-up 143 patients with a hallux valgus and simultaneous pes adductus deformity who underwent one of three additional interventions contemporaneous to the lateralising DMMO: The assessment of radiological and clinical outcomes after a follow-up period of 12-25 months showed a sustained and effective correction of the pes adductus with a well-aligned hallux. The surgery was characterised by a low incidence of postoperative complications and high patient satisfaction while allowing for pain-adapted, post-operative weight-bearing. Level of Clinical Evidence: 3.

Comparison of Ligament-Repair Techniques for the Syndesmosis: A Simulated Cadaveric Weight-Bearing Computed Tomography Analysis.

Although the literature describes a variety of reconstructive techniques for the syndesmosis, only few studies offer comparative data. Therefore, the authors compared 2 different ligament repair techniques for the syndesmosis. Sixteen paired fresh-frozen human cadaveric lower limbs were embedded in polymethyl methacrylate mid-calf and placed in a custom-made weightbearing simulation frame. Computed tomography scans of each limb were obtained in a simulated foot-flat loading (75N) and single-leg stance (700N) in 5 different foot positions (previously reported data). One of each pair was then reconstructed via 1 of 2 methods: a free medial Achilles tendon autograft or a long peroneal tendon ligament repair. The specimens were rescanned, compared with their respective intact states and directly with each other. Measurements of fibular diastasis, rotation, anteroposterior translation, mediolateral translation, and fibular shortening were performed on the axial cuts of the computed tomography scans, 1 cm proximal to the roof of the plafond. There was no significant difference in fibular positioning with direct comparison of the reconstructions. Comparisons with their respective intact states, however, showed differences in their abilities to control reduction, most notably in the externally rotated and dorsiflexed positions of the foot. Neither reconstruction was clearly superior in restoring physiologic conditions. Only with a comparison of each technique to its respective intact state were differences between the techniques revealed, a benefit of this particular testing method.

Impact of surgical procedures on soft tissue microcirculation in calcaneal fractures: A prospective longitudinal cohort study.

PURPOSE: Wound healing complications are a major concern after open reduction and internal fixation (ORIF) in patients with calcaneal fractures. Microcirculation is known to play a key role in bone and soft tissue healing. The present study aimed to characterize and contrast the dynamics of changes in microcirculation comparing two different surgical procedures: A) ORIF and B) a minimally invasive approach (MIA). METHODS: Blood flow (BF[AU]), oxygen saturation (sO2[%]) and relative amount of haemoglobin (rHb[AU]) were measured at two depths (2 mm and 8 mm) non-invasively by spectrophotometry (Micro-Lightguide O2C®, LEA Medizintechnik, Giessen, Germany) before surgery and every 24 h after surgery for a duration of six days. A linear mixed model (LMM) was used to analyse longitudinal data and repeated measurements. RESULTS: Nineteen patients (44 years, range 21.9-71.0 years) were enrolled in the study. Surgical treatment consisted of ORIF (n = =15) and MIA (n = =9). The postoperative BF and sO2 at the 2 mm and 8 mm depths were higher in the ORIF group (BF: p < 0.001, p = =0.003; sO2: p = =0.001, p = =0.011). The BF at the 2 mm and 8 mm depths increased after surgery (2 mm: p = =0.003, 8 mm: p = =0.001) in both groups. This increase did not correlate with the surgical technique. sO2 and rHb values at the 8 mm depth decreased after surgery (sO2: p = =0.008, rHb: p < 0.001) in both groups, whereas sO2 at the 2 mm depth increased after surgery (p = =0.003). Furthermore, the surgical technique correlated with the postsurgical course of sO2 values at the 2 mm depth (p = =0.042). CONCLUSIONS: The spectrophotometry results were in line with the generally accepted phases of soft tissue wound healing. Postsurgical changes in microcirculation are predominantly independent of surgical techniques and may be primarily determined by wound and fracture healing. Future studies should focus on the potential of spectrophotometry to monitor wound healing after surgery. Moreover, studies with longer observation periods are needed in order to examine the changes in microcirculation during all wound-healing phases.