Lauren Roberts

Open Re-rupture of the Achilles Tendon Following Minimally Invasive Repair: A Case Report

In this report, we describe a rare complication of an open re-rupture of the Achilles tendon following a minimally invasive Achilles tendon repair on a healthy 29-year-old active male. The reinjury happened 19 weeks following the primary surgical repair of a spontaneous rupture, performed by minimally invasive technique with the help of a jig using partially absorbable sutures and four locking stitches. The wound of the open re-rupture was transverse, in a perpendicular orientation relative to the longitudinal approach used in the index procedure. Increased scar tissue formation, the absence of an adequate layer of paratenon overlying the primary tendon repair, and foreign-body reaction to the suture may have been involved in the occurrence of this unusual complication in the surgical treatment of Achilles tendon rupture.

Intraoperative tap test for coronal syndesmotic instability: A cadaveric study

INTRODUCTIONnPrecise diagnosis of distal tibiofibular syndesmotic injury is challenging, and a gold standard diagnostic test has still not been established. Tibiofibular clear space identified on radiographic imaging is considered the most reliable indicator of the injury. The Cotton test is the most widely used intraoperative technique to evaluate the syndesmotic integrity although it has its limitations. We advocate for a novel intra operative test using a 3.5u2009mm blunt cortical tap.nnnMETHODSnTibiofibular clear space was assessed in nine cadaveric specimens using three sequential fluoroscopic images. The first image was taken prior to the application of the tap test (intact, non-stressed). Then, a 2.5u2009mm hole was drilled distally on the lateral fibula, and a 3.5u2009mm cortical tap was then threaded in the hole. The tap test involved gradually advancing the blunt tip against the lateral tibia, providing a tibiofibular separation force (intact, stressed). This same stress was then applied after all syndesmotic ligaments were released (injured, stressed). Measurements were compared by one-way ANOVA and paired Students t-test. Intra and inter-observer agreements were evaluated by intraclass correlation coefficient (ICC). P-values <.05 were considered significant.nnnRESULTSnWe found excellent intra-observer (0.97) and inter-observer (0.98) agreement following the imaging assessment. Significant differences were found in the paired comparison between the groups (pu2009<u2009.05). When using an absolute value for TFCS >6u2009mm as diagnostic for coronal syndesmotic instability, the tap test demonstrated a 96.3% sensitivity and specificity, a 96.3% PPV and NPV and a 96.3% accuracy in diagnosing coronal syndesmotic instability.nnnCONCLUSIONSnOur cadaveric study demonstrated that this novel coronal syndesmotic instability test using a 3.5u2009mm blunt cortical tap is a simple, accurate and reliable technique able to demonstrate significant differences in the tibiofibular clear space when injury was present. It could represent a more controlled and stable alternative to the most used Cotton test.

The success rate of First Metatarsophalangeal Joint Lateral Soft Tissue Release through a Medial Transarticular Approach: A Cadaveric Study

BACKGROUNDnThe objective of this study was to evaluate the success rate of first metatarsophalangeal joint (MTPJ) lateral soft tissue release through a medial transarticular approach.nnnMETHODSnTen cadaveric specimens were used (6 females/4 males, mean age, 73.4years). Lateral release was performed through a 4cm medial approach using a number 15 blade. Surgical aim was to release four specific structures: lateral capsule, lateral collateral ligament (LCL), adductor hallucis tendon (AHT) and lateral metatarsosesamoid suspensory ligament (LMSL). Once completed, a dissection of the first intermetatarsal space was performed. Success rate was graded in accordance to the number of structures successfully released: 0% (no structures), 25% (1/4), 50% (2/4), 75% (3/4) and 100% (4/4). Inadvertent injuries to other soft tissue structures were recorded.nnnRESULTSnThe success rate for lateral soft tissue release was 100% in 7 cadaveric specimens, and respectively 75%, 50% and 25% in the other 3 specimens. The LCL was successfully released in all specimens. The lateral joint capsule, AHT and LMSL were released in 80% of the specimens. Chondral damage to the first metatarsal head, unintended release of the conjoined tendon and lateral head of the flexor hallucis brevis (FHB) occurred respectively in 40%, 50% and 20% of the specimens.nnnCONCLUSIONSnOur cadaveric study demonstrated high success rate in the release of specific lateral soft tissue structures of the first MTPJ through a medial transarticular approach. Inadvertent release of the lateral head of the FHB, conjoined tendon and iatrogenic chondral damage of the first metatarsal head are complications to be considered.nnnLEVEL OF EVIDENCEnCadaveric study - Level V.

Percutaneous Posterior to Anterior Screw Fixation of the Talar Neck: Soft Tissue Structures at Risk

Category: Trauma Introduction/Purpose: Fractures of the talar neck and body can be fixed with percutaneously placed screws directed from anterior to posterior or posterior to anterior. The latter has been found to be biomechanically and anatomically superior. Percutaneous pin and screw placement poses anatomic risks for posterolateral and posteromedial neurovascular and tendinous structures. The objective of this study was to enumerate the number of trials for proper placement of two parallel screws and to determine the injury rate to neurovascular and tendinous structures. Methods: Eleven fresh frozen cadaver limbs were used. 2.0 mm guide wires from the Stryker (Selzach, Switzerland) 5.0-mm headless cannulated set were percutaneously placed (under fluoroscopic guidance) into the distal posterolateral aspect of the ankle. All surgical procedures were performed by a fellowship-trained foot and ankle surgeon. Malpositioned pins were left intact to allow later assessment of soft tissue injury. The number of guide wires needed to achieve an acceptable positioning of the implant was noted. Acceptable positioning was defined as in line with the talar neck axis in both AP and lateral fluoroscopic views. After a layered dissection from the skin to the tibia, we evaluated neurovascular and tendinous injuries, and measured the shortest distance between the closest guide pin and the soft tissue structures, using a precision digital caliper. Results: The mean number of guide wires needed to achieve acceptable positioning for 2 parallel screws was 2.91 ± 0.70 (range, 2 - 5). The mean distances between the closest guide pin and the soft tissue structures of interest were: Achilles tendon, 0.53 ± 0.94 mm; flexor hallucis longus tendon, 6.62 ± 3.24 mm; peroneal tendons, 7.51 ± 2.92 mm; and posteromedial neurovascular bundle, 11.73 ± 3.48 mm. The sural bundle was injured in all the specimens, with 8/11 (72.7%) in direct contact with the guide pin and 3/11 (17.3%) having been transected. The peroneal tendons were transected in 1/11 (9%) of the specimens. The Achilles tendon was in contact with the guide pin in 6/11 (54.5%) specimens and transected in 2/11 (18.2%) specimens. Conclusion: The placement of posterior to anterior percutaneous screws for talar neck fixation is technically demanding and multiple guide pins are needed. Our cadaveric study showed that important tendinous and neurovascular structures are in close proximity with the guide pins and that the sural bundle was injured in 100% of the cases. We advise performing a formal small posterolateral approach for proper visualization and retraction of structures at risk. Regardless, adequate patient education about the high risk of injury from this procedure is crucial.

Ankle Fusion Percutaneous Home Run Screw Fixation: technical aspects and soft tissue structures at risk

Category: Ankle Arthritis Introduction/Purpose: During internal fixation of ankle fusions, besides the standard crossed screw fixation pattern, the use of a percutaneously placed augmenting screw, directed from the posterolateral tibial metaphysis proximally across the ankle into the talar neck (“ankle fusion home run screw”), is a widely used technique. The placement of this screw is technically demanding and multiple attempts under fluoroscopy guidance are frequently needed to achieve a perfect positioning of the implant. Injuries to local neurovascular and tendinous structures might happen. The objective of this cadaver study was to identify the number of attempts necessary for a perfect positioning of the ankle fusion home run screw and the neurovascular and tendinous structures at risk. Methods: Eleven fresh frozen cadaver limbs were used. Guide wires (3.2 mm) from the Stryker (Selzach, Switzerland) 7.0-mm headless cannulated set were percutaneously placed into the distal posterolateral aspect of the leg, under fluoroscopic guidance, with the ankle held in neutral position. Mal positioned pins were not removed and served as guidance for the following pins. The number of guide wires needed to achieve an acceptable positioning of the implant was noted. After a layered dissection from the skin to the tibia, we evaluated neurovascular and tendinous injuries, and measured the shortest distance between the closest guide pin and the soft tissue structures, using a precision digital caliper. Results: The mean number of guide wires needed to achieve and acceptable positioning of the implant was 2.09 (SD 0.83, range 1- 4). The mean distances between the closest guide pin and the soft tissue structures of interest were: Achilles tendon 6.90 mm (SD 3.74 mm); peroneal tendons 9.65 mm (SD 3.99 mm); sural neurovascular bundle 0.97 mm (SD 1.93 mm); posteromedial neurovascular bundle 14.26 mm (SD 4.56 mm). Sural bundle was in contact with the guide pin in 5/11 specimens (45.5%) and transected in 3/11 specimens (27.3%). Conclusion: The placement of percutaneous ankle fusion home run screws is technically demanding and multiple guide pins are needed. Our cadaveric study showed that important tendinous and neurovascular structures are in close proximity with the guide pins and that the sural bundle is injured in approximately 73% of the cases. Caution should be taken during percutaneous placing of screws and an appropriate approach and surgical dissection to bone is advised.

Soft Tissue Structures at Risk With Percutaneous Posterior to Anterior Screw Fixation of the Talar Neck

Background: Fractures of the talar neck and body can be fixed with percutaneously placed screws directed from anterior to posterior or posterior to anterior. The latter has been found to be biomechanically and anatomically superior. Percutaneous guidewire and screw placement poses anatomic risks for posterolateral and posteromedial neurovascular and tendinous structures. The objective of this study was to determine the injury rate to local neurovascular and tendinous structures using this technique in a cadaveric model. In addition, we aimed to determine the number of attempts at passing the guidewires required to achieve acceptable placement of 2 parallel screws. Methods: Eleven fresh frozen cadaver limbs were used. Two 2.0-mm guidewires were placed under fluoroscopic guidance, posterior to anterior centered within the talus. The number of attempts required was recorded. A layered dissection was then performed to identify injury to any local anatomic structure. The shortest distance between the closest guidewire and the soft tissue structures was measured. Results: The mean total number of guidewires passed to obtain optimal placement of 2 parallel screws was 2.9 ± 0.7. Direct contact between the guidewire and the sural nerve was seen in 100% of the specimens, with the nerve impaled by the guidewire in 3 of 11 (27.2%) cases. The peroneal tendons were impaled in 1 of 11 (9%) specimens and the Achilles tendon was in contact with the guidewire in 8 of the 11 (72.7%) specimens, and impaled at its most lateral border with the guidewire in 2 specimens (18.2%). Conclusion: The placement of posterior to anterior percutaneous screws for talar neck fixation is technically demanding, and multiple guidewires are needed. Our cadaveric study showed that important tendinous and neurovascular structures were in proximity with the guidewires and that the sural nerve was injured in 100% of the cases. Clinical Relevance: Given the risk of injury to these structures, we recommend a formal posterolateral incision for proper visualization and retraction of the anatomic structures at risk.