Biomechanics of the unstable ankle joint and clinical implications

Reconstruction of the Medial Malleolus With Iliac Crest Autograft After Traumatic Loss: A Case Report

CASE

A 19-year-old woman sustained an open ankle fracture with complete destruction of the left medial malleolus and significant soft-tissue loss. After temporizing external fixation and coverage with a rotational posterior tibial artery perforator flap, the medial malleolus was reconstructed with an autologous iliac crest bone graft and direct repair of the deltoid ligament. The patient achieved excellent improvement in functional outcomes at 21 months with adequate restoration of ankle motion.

CONCLUSION

This case shows reconstruction of the medial malleolus with autologous iliac crest bone graft after traumatic loss can be a viable treatment option for young patients.

[Complex Regional Pain Syndrome (CRPS) - State of the Art in Diagnostics and Therapy]

The complex regional pain syndrome (CRPS) usually occurs within a few weeks in 2-5% of all patients after trauma or surgery or subsequent measures of the distal extremities. There are certain risk factors for its occurrence but no "CRPS personality", instead there are factors that negatively influence the course. The prognosis is generally good ("rule of thirds"), but remaining limitations are common. The diagnosis is clinically possible according to the "Budapest criteria". Additional examinations are possible in case of doubt but are neither conclusive nor exclusive. Corticoids and bisphosphonates are used alongside drugs that have an effect on neuropathic pain. Invasive therapies do not have good evidence and have therefore lost their importance. The rehabilitative therapy is carried out actively and with a lot of self-exercises at an early stage. Invasive anesthetic, passive therapies are obsolete. Special forms of treatment are "graded exposure" (GEXP) in the case of dominant anxiety and, e.g., "graded motor imagery" (GMI) in case of neglect-like symptoms. In addition to educational and behavioral therapy elements, psychotherapy for CRPS also includes participation as part of graded exposure.

Role of the intrinsic subtalar ligaments in subtalar instability and consequences for clinical practice

Subtalar instability (STI) is a disabling complication after an acute lateral ankle sprain and remains a challenging problem. The pathophysiology is difficult to understand. Especially the relative contribution of the intrinsic subtalar ligaments in the stability of the subtalar joint is still controversial. Diagnosis is difficult because of the overlapping clinical signs with talocrural instability and the absence of a reliable diagnostic reference test. This often results in misdiagnosis and inappropriate treatment. Recent research offers new insights in the pathophysiology of subtalar instability and the importance of the intrinsic subtalar ligaments. Recent publications clarify the local anatomical and biomechanical characteristics of the subtalar ligaments. The cervical ligament and interosseous talocalcaneal ligament seem to play an important function in the normal kinematics and stability of the subtalar joint. In addition to the calcaneofibular ligament (CFL), these ligaments seem to have an important role in the pathomechanics of subtalar instability (STI). These new insights have an impact on the approach to STI in clinical practice. Diagnosis of STI can be performed be performed by a step-by-step approach to raise the suspicion to STI. This approach consists of clinical signs, abnormalities of the subtalar ligaments on MRI and intraoperative evaluation. Surgical treatment should address all the aspects of the instability and focus on a restoration of the normal anatomical and biomechanical properties. Besides a low threshold to reconstruct the CFL, a reconstruction of the subtalar ligaments should be considered in complex cases of instability. The purpose of this review is to provide a comprehensive update of the current literature focused on the contribution of the different ligaments in the stability of the subtalar joint. This review aims to introduce the more recent findings in the earlier hypotheses on normal kinesiology, pathophysiology and relation with talocrural instability. The consequences of this improved understanding of pathophysiology on patient identification, treatment and future research are described.

Decreasing the Abnormal Internally Rotated Talus After Lateral Ankle Stabilization Surgery

Background

Increased internal rotation of the talus has been found in patients with mechanical ankle instability (MAI).

Purpose/Hypothesis

To evaluate and compare the talar rotation position before and after lateral ankle lateral stabilization surgery in patients with MAI. We hypothesized that the abnormal internal talus rotation in patients with MAI will decrease after surgery for ankle lateral instability and that there will be no significant difference in internal talus rotation between the ligament repair and reconstruction groups.

Study Design

Case-control study; Level of evidence, 3.

Methods

We retrospectively studied 56 patients with MAI who underwent ankle lateral stabilization surgery after arthroscopic evaluation (repair, 36 cases; reconstruction, 20 cases). Before and after the operation, magnetic resonance images of all the participants were reviewed. The rotated position of the talus was measured and calculated by the Malleolar Talus Index at the magnetic resonance axial plane.

Results

The internal rotation of the talus decreased significantly after ankle lateral stabilization surgery in patients with MAI as compared with before surgery (mean ± SD, 83.3° ± 3.3° vs 86.7° ± 3.9°; P < .01). However, there was no statistically significant difference between the ligament repair and reconstruction groups before or after the operation.

Conclusion

Abnormal internal rotation of the talus in patients with MAI was decreased after ankle lateral stabilization surgery.

Magnetic resonance imaging of ankle ligaments: A pictorial essay

Ankle trauma is commonly encountered and is most often a sprain injury affecting the ligaments. Accurate diagnosis and appropriate treatment rest on knowledge of complex ligamentous anatomy of ankle and the entire spectrum of pathologies. Magnetic resonance imaging (MRI) is the imaging modality of choice for diagnosing ligament pathologies because of its multiplanar capability and high soft tissue contrast. With MRI, it is possible to triage and attribute the cause of post traumatic ankle pain to bone, ligament, or tendon pathologies, which otherwise overlap clinically. In this pictorial essay, emphasis is given to the intricate and unique anatomy and orientation of ankle ligaments. Pathologies of ankle ligaments have been elaborated.

Clinical Appearance of Medial Ankle Instability

Whereas tenderness, ecchymosis, and swelling over the deltoid ligament have relatively poor sensitivity, resulting valgus and pronation deformity that is seen to disappear when the patient is asked to activate the posterior tibial muscle or to go in tiptoe position is the hallmark for the presence of medial ankle instability. A pain on palpation at anteromedial edge of the ankle confirms the diagnosis. Various stress tests permit to confirm and specify the injury pattern. A pseudo hallux rigidus is the consequence of a hyperactivity of flexor hallucis longus muscle to protect the foot against the valgus and pronation deformity.

The anterior talofibular ligament-posterior talofibular ligament angle decreased after ankle lateral stabilization surgery

PURPOSE

The angle between the anterior talofibular ligament (ATFL) and the posterior talofibular ligament (PTFL) is increased in patients with chronic ATFL injury. This study aimed to compare the AFTL-PTFL angle before versus after ankle lateral stabilization surgery, and to evaluate whether the ATFL-PTFL angle correlates with the ligament injury severity.

METHODS

This retrospective study included 48 patients with mechanical ankle instability treated between 2016 and 2018. After arthroscopic evaluation, all patients underwent ankle lateral stabilization surgery comprising ligament repair (n = 28) or reconstruction (n = 20). The ATFL-PTFL angle was measured in the axial plane on pre- and postoperative MRI. Comparisons were made of the pre- versus postoperative ATFL-PTFL angles, and the ATFL-PTFL angle of the repair versus reconstruction groups. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of the ATFL-PTFL angle in selecting the surgical technique.

RESULTS

The postoperative ATFL-PTFL angle was significantly decreased compared with preoperatively. The ATFL-PTFL angle was significantly smaller in the repair group than the reconstruction group preoperatively and postoperatively. The area under the ROC curve was 0.741 (P < 0.01). The optimal cutoff point for the selection of ligament reconstruction was an ATFL-PTFL angle of 89.4° (sensitivity 0.85, specificity 0.61).

CONCLUSION

The ATFL-PTFL angle decreases after ankle lateral stabilization surgery. The ATFL-PTFL angle is related to the severity of the ATFL injury. Ankle lateral ligament reconstruction should be considered when the ATFL-PTFL angle is > 89.4°.

LEVEL OF EVIDENCE

Level III.

The effect of the combination of whole body vibration and shoe with an unstable surface in chronic ankle instability treatment: a randomized clinical trial

Background

Chronic ankle instability (CAI) is a common condition following an ankle sprain. This study investigated the effects of whole body vibration (WBV) and shoe with an unstable surface training on balance, functional performance, strength, joint position sense in people with CAI.

Method

Thirty- four peoples with unilateral CAI were randomly assigned to three groups: WBV group, WBV with shoe with an unstable surface (WBV-S), and no treatment control group (CON). The WBV group received 4 weeks progressive WBV training and the WBV-S group received progressive WBV training with shoe with an unstable surface. Modified star excursion balance test (mSEBT)reach distance, Hop-Test, muscle strength, and joint position sense were measured at baseline and after the 4 weeks; Moreover, the mSEBT and Hop-Test were reassessed again 2 weeks post intervention.

Results

The result showed a significant group-by-time interaction for anterior and posterolateral directions of mSEBT. The reach distance of these directions at post-intervention and follow-up increased significantly compare to pre-intervention in the WBV and WBV-S groups but not significantly change in the CON group. The Hop test in the WBV-S group was significantly more at post-intervention and follow-up compared to pre-intervention. However, no significant changes were observed in WBV and CON groups. No significant changes were observed for mSEBT posteromedial direction, muscles strength, and joint position sense errors.

Conclusion

The 4 weeks WBV and WBV-S interventions could improve balance in peoples with CAI. Improvement in Hop test was only observed in the WBV-S group suggesting the added value of combining WBV and shoe with an unstable surface as an effective therapy compared to WBV training alone. The use of WBV and WBV-S were not associated with significant changes in strength and joint position sense variables over a four-week period.

Trial registration

This work registered in the Iranian Registry of Clinical Trials (IRCT20151118025105N4).

Modern Open and Minimally Invasive Stabilization of Chronic Lateral Ankle Instability

Chronic lateral ankle instability is the sensation of the ankle giving way along with recurrent sprains, chronic pain and swelling of the ankle for 1 year. The lateral ankle complex comprises the anterior talofibular ligament, calcaneofibular ligament, and posterior talofibular ligament. The anterior talofibular ligament is the most commonly injured ligament of the lateral ankle. Evaluation comprises a history and physical with concomitant imaging to confirm the diagnosis and can be used to evaluate for concurrent pathology. The most popular treatment is a direct anatomic repair; however, additional options can be used in specific patient populations.

Foot impairments contribute to functional limitation in individuals with ankle sprain and chronic ankle instability

PURPOSE

To investigate the clinical measures of foot posture and morphology, multisegmented joint motion and play, strength, and dynamic balance in recreationally active young adults with and without a history of a lateral ankle sprain (LAS), copers, and chronic ankle instability (CAI).

METHODS

Eighty recreationally active individuals (healthy: n = 22, coper: n = 21, LAS: n = 17, CAI: n = 20) were included. Foot posture index (FPI), morphologic measures, joint motion (weight-bearing dorsiflexion (WBDF), rearfoot dorsiflexion, plantar flexion, inversion, eversion; forefoot inversion, eversion; hallux flexion, extension), joint play (proximal and distal tibiofibular; talocrural and subtalar, forefoot; 1st tarsometatarsal and metatarsophalangeal), strength (dorsiflexion, plantar flexion, inversion, eversion, hallux flexion, lesser toe flexion), and Star Excursion Balance Test (SEBT) (anterior, posteromedial, posterolateral) were assessed.

RESULTS

There were no group differences in FPI or morphological measures. LAS and CAI groups had decreased ankle dorsiflexion (p = 0.001) and greater frontal plane motion (p < 0.001), first MT plantar flexion, and sagittal excursion (p < 0.001); increased talocrural glide (p = 0.02) and internal rotation (p < 0.001) and decreased forefoot inversion joint play (p < 0.001); and decreased strength in all measures (p < 0.001) except dorsiflexion compared to healthy controls. The LAS group also demonstrated decreased distal tibiofibular (p = 0.04) and forefoot general laxity (p = 0.05) and SEBT performance (anterior: p = 0.02; posteromedial: p < 0.001; posterolateral: p < 0.001).

CONCLUSION

Individuals with LAS or CAI have increased pain, impaired physiologic and accessory joint motion, ligamentous tenderness, and strength in the foot and ankle. Clinicians should assess the multiple segments of the ankle-foot complex when caring for individuals with an LAS or CAI.

LEVEL OF EVIDENCE

II.

Arthroscopic all-inside anterior talo-fibular ligament repair with suture augmentation gives excellent results in case of poor ligament tissue remnant quality

PURPOSE

An increasing role of arthroscopy as the definitive treatment for ankle instability has been reported, and assisted or all-arthroscopic techniques have been developed. However, treatment of chronic ankle instability with poor remnant ligament-tissue quality is still challenging. The aim of this study was to describe the technique and report the results of the arthroscopic ATFL all-inside repair with suture augmentation to treat patients with poor remnant ligament-tissue quality.

METHODS

Fifteen patients [9 men and 6 women, median age 30 (19-47) years] with chronic ankle instability and poor remnant ligament-tissue quality were treated by arthroscopic means after failing non-operative management. Median follow-up was 18 (12-23) months. Through an arthroscopic all-inside technique, and using a suture passer and two knotless anchors, the ligament was repaired. Then, the anchor's residual suture limbs were not cut, but were recycled and used for augmentation of the ligament repair.

RESULTS

Arthroscopic examination demonstrated an isolated anterior talofibular ligament (ATFL) injury with poor remnant ligament tissue in the 15 patients. All patients reported subjective improvement in their ankle instability after the arthroscopic all-inside ligaments repair and suture augmentation. The median AOFAS score increased from 66 (44-87) preoperatively to 100 (85-100) at the final follow-up.

CONCLUSION

Chronic ankle instability with poor remnant ligament-tissue quality can be successfully treated by an arthroscopic all-inside repair and suture augmentation of the ligament. The clinical relevance of the study is the description of the first arthroscopic all-inside anatomic ATFL repair with suture augmentation that offers the benefit of maintaining the native ligament while reinforcing the repair, especially in patients with poor remnant ligament-tissue quality.

LEVEL OF EVIDENCE

IV, retrospective case series.

Assessing mechanical ankle instability via functional 3D stress-MRI - A pilot study

BACKGROUND

Quantitative measurement of the mechanical deficit in chronic ankle instability (CAI) is difficult. Therefore, the distinction between functional (FAI) and mechanical ankle instability (MAI) as well as the evaluation of surgical techniques is difficult. This pilot study uses a novel method of functional 3-dimensional stress ankle-MRI to test its applicability for assessing mechanical ankle instability.

METHODS

We used a custom-built ankle arthrometer that allows a stepless positioning of the foot and an axial in situ loading with up to 500 N combined with a 3-dimensional MRI protocol. We assessed four parameters (3D cartilage contact area (CCA) fibulotalar, tibiotalar horizontal and vertical and intermalleolar distance) under six different conditions (neutral-null, plantarflexion-supination and dorsiflexion-pronation each with and without loading) in n = 10 individuals (7 suffering from MAI and 3 healthy controls).

FINDINGS

The MAI group showed a substantially increased reduction of lateral osseous constraint compared to healthy controls when the foot was positioned in plantarflexion-supination (CCA fibulotalar 69% vs. 30% in controls). The reduction of the weight bearing surface in plantarflexion-supination was also more pronounced (CCA tibiotalar horizontal -49% in MAI vs. -28% in controls).

INTERPRETATION

This novel technique is valuable for assessing mechanical ankle instability in the target population and has a potential clinical benefit for assessing the mechanical deficit of individual patients. Further studies are needed to provide evidence for a possible prognostic value of this novel technique.

In vivo arthrometer measurements of mechanical ankle instability-A systematic review

Chronic ankle instability is caused by functional and/or mechanical deficits. To differentiate the two entities, mechanical ankle instability can be assessed using arthrometers. The measurement of mechanical instability is essential, since it can only be addressed surgically. The aim of this systematic literature review was to find out whether chronic mechanical ankle instability could be adequately and objectively assessed using in vivo arthrometer measurements. Articles were included if the main focus was to evaluate the contribution of mechanical deficits to chronic ankle instability and if they provided sufficient description of the device used. This systematic review was performed according to the PRISMA-recommendations. Initially 47 articles were screened for eligibility, of which 33 studies reporting 10 different devices were included. While the reliability of the measurements was mostly good to excellent, only two studies aimed to assess the sensitivity and specificity of their results in regard to chronic ankle instability. Several devices reported conflicting results about mechanical deficits. In summary, this systematic review reveals a substantial deficit in diagnostic accuracy when assessing mechanical ankle instability in a clinical setting. Biases in recruiting and classification of participants raise the question whether the two entities of functional and mechanical ankle instability are properly defined. Clinical Significance: In recent years, this may have led to a misinterpretation of mechanical deficits and the subsequent need for surgical intervention. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

[Arthroscopic repair of chronic lateral ankle instability]

OBJECTIVE

Repair of the lateral ligament complex of the ankle joint; identification and treatment of intra-articular pathologies.

INDICATIONS

Symptomatic chronic lateral ankle instability. Treatment of osteochondral lesions associated with lateral ankle instability.

CONTRAINDICATIONS

Osteoarthritis of the ankle joint, risk factors such as peripheral occlusive disease, diabetic foot syndrome, complex regional pain syndrome.

SURGICAL TECHNIQUE

Diagnostic arthroscopy of the ankle joint utilizing anterolateral and -medial portals; identification and treatment of intra-articular pathologies; identification and preparation of the distal fibula; insertion of two suture anchors; the sutures are passed inside-out through the joint capsule, the scarred lateral ligaments, the extensor retinaculum using a suture lasso; by tying down the sutures the tissue grasped is then pulled against the distal fibula; this will stabilize the lateral ligament complex.

POSTOPERATIVE MANAGEMENT

Partial weight-bearing and short leg cast for 2 weeks, then 4 weeks ankle brace and range of motion exercises, thereafter functional physical therapy, ankle brace only during exercises; no sports for at least 3 months.

RESULTS

Currently, one randomized controlled trial is available comparing open to arthroscopic lateral ankle ligament repair. Open repair was always combined with arthroscopy to treat intra-articular pathologies. In all patients, surgery led to a significant increase of the American Orthopaedic Foot and Ankle Score (AOFAS), Karlsson Score and visual analog score (VAS), but no significant differences between the open and arthroscopic procedure after one year with similar complications (arthroscopy group: 3 temporary nerve irritations and 2 patients with pain over the knot; open treated group: 2 temporary nerve irritations and one abscess). Intra-articular pathologies were treated in 68% of the arthroscopically treated patients and 70% of the patients treated by open surgery. One out of two retrospective comparative studies reported a significantly shorter operation time and time to return to daily activity and significantly lower VAS three days postoperatively for arthroscopically treated patients, while the other parameters assessed were comparable.

No Difference between Percutaneous and Arthroscopic Techniques in Identifying the Calcaneal Insertion during Ankle Lateral Ligament Reconstruction: A Cadaveric Study

Background. Both percutaneous and arthroscopic techniques have been introduced in anatomic ankle lateral ligaments reconstruction. The purpose of this study was to compare these two techniques in identifying the calcaneal insertion of the calcaneofibular ligament (CFL). Methods. Fifteen fresh-frozen human ankle cadaver specimens were used in this study. Each specimen was tested in three stages. For stage 1, each specimen was evaluated under arthroscopy. After debridement was performed, the insertion of the CFL on the calcaneus was identified, and a 1.5mm Kirschner wire was drilled at the center of the insertion. For stage 2, a percutaneous technique was used to identify the center of the insertion of the CFL. A second 1.5 mm Kirschner wire was drilled through the skin marker. For stage 3, the ankle was dissected, the footprint of the CFL was identified under direct vision, and the distances between the center of the CFL insertion on the calcaneus and the two Kirschner wires were measured, respectively. Results. In the arthroscopic technique group, the mean distance from the Kirschner wire to the center of the CFL insertion in the calcaneus was 3.4 ± 1.3 mm. In the percutaneous technique group, the mean distance from the Kirschner wire to the center of the CFL insertion was 3.2 ± 1.4 mm. No significant difference was found between the two groups. Conclusion. No difference in identifying the calcaneal insertion of the CFL was found between the percutaneous and the arthroscopic ankle lateral ligaments reconstruction technique. Both techniques can be used during anatomic ligaments reconstruction in treatment of chronic ankle instability.

Anatomic validation of the lateral malleolus as a cutaneous marker for the distal insertion of the calcaneofibular ligament

PURPOSE

An anatomic study was performed to confirm whether the lateral malleolus could serve as a simple and reproducible anatomic reference for the distal insertion of the calcaneofibular ligament (CFL).

METHODS

Dissection was performed after placement of a Kirschner wire to simulate the calcaneal tunnel for the distal insertion of the CFL. The skin was penetrated 1 cm distal and posterior to the tip of the lateral malleolus. The main information recorded was the distance from the Kirschner wire to the centre of the distal insertion of the CFL. Other elements were noted (characteristics of the CFL, distance between the distal insertion of the CFL-peroneal tubercle, nerve or tendon injuries).

RESULTS

Thirty ankles were dissected. The mean distance from the Kirschner wire to the centre of the distal insertion of the CFL was 2.4 ± 1.8 mm. Only one case of peroneal injury was noted. The sural nerve was usually located a mean 1.8 ± 1.1 mm from the Kirschner wire. The posterior tibial vascular pedicle was a mean 27.8 ± 3.5 mm from the point of exit of the Kirschner wire.

CONCLUSION

Using the lateral malleolus as the cutaneous reference for the distal insertion of the CFL seems to be more reliable than the pure arthroscopic technique. This study describes a percutaneous technique to obtain a calcaneal tunnel for distal insertion of the CFL. The sural nerve is at the greatest risk of injury with this technique and requires careful subcutaneous incision to prevent injury. This new percutaneous technique is less invasive than a purely arthroscopic technique and more accurately identifies the location of the tunnel. It can be used to do calcaneal tunnel in clinical practice during anatomic ligament reconstruction for chronic ankle instability.

Allograft tendon reconstruction of the anterior talofibular ligament and calcaneofibular Ligament in the treatment of chronic ankle instability

Background

The purpose was retrospectively to investigate functional and clinical outcomes after anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) reconstruction using a single allograft.

Methods

Patients with severe chronic lateral instability of the ankle underwent surgery after conservative treatment failed. Ultrasounds of the ankle were performed, and if the AFTL and CFL were completely torn without enough soft tissue for repair, the ligaments were reconstructed using allograft tendon. Outcomes were assessed by clinical examination, stress radiography, ultrasound, the American Orthopaedic Foot and Ankle Society score (AOFAS), and Karlsson Ankle Functional score (KAFS) before surgery and at final follow-up.

Results

Nineteen patients, ten men and nine women with mean age of 27.9 years (range, 19–41 years), underwent reconstruction. Mean follow-up was 30 months (range, 24–40 months). At final follow-up, all patients had returned to activity without instability, pain, or limited range of motion. On stress radiography, mean talar tilt angle decreased from 17.32° ± 3.58° before surgery to 4.16° ± 1.12° at follow-up (p < 0.001). Mean anterior drawer test (ADT) distance decreased from 9.79 ± 1.01 mm before surgery to 3.97 ± 0.99 mm at follow-up (p < 0.05). Mean AOFAS improved from 64.00 ± 18.43 to 90.32 ± 5.17 points (p < 0.001), and mean KAFS improved from 50.84 ± 16.73 to 90.89 ± 5.08 points (p < 0.001). Ultrasound showed the reconstructed ligaments maintained good continuity and excellent tension. No case of infection and immunological rejection was reported.

Conclusion

This novel reconstruction technique takes into account the anatomical specialty of AFTL and CFL. This case series showed increased stability of the ankle in clinical and functional outcomes.

Trial registration

The trial registration number (TRN) and date of registration: ChiCTR-ORC-17010796, Mar 6th 2017. Retrospectively registered.

Determination of the in situ mechanical behavior of ankle ligaments

The mechanical behavior of ankle ligaments at the structural level can be characterized by force-displacement curves in the physiologic phase up to the initiation of failure. However, these properties are difficult to characterize in vitro due to the experimental difficulties in replicating the complex geometry and non-uniformity of the loading state in situ. This study used a finite element parametric modeling approach to determine the in situ mechanical behavior of ankle ligaments at neutral foot position for a mid-sized adult foot from experimental derived bony kinematics. Nine major ankle ligaments were represented as a group of fibers, with the force-elongation behavior of each fiber element characterized by a zero-force region and a region of constant stiffness. The zero-force region, representing the initial tension or slackness of the whole ligament and the progressive fiber uncrimping, was identified against a series of quasi-static experiments of single foot motion using simultaneous optimization. A range of 0.33-3.84mm of the zero-force region was obtained, accounting for a relative length of 6.7±3.9%. The posterior ligaments generally exhibit high-stiffness in the loading region. Following this, the ankle model implemented with in situ ligament behavior was evaluated in response to multiple loading conditions and proved capable of predicting the bony kinematics accurately in comparison to the cadaveric response. Overall, the parametric ligament modeling demonstrated the feasibility of linking the gross structural behavior and the underlying bone and ligament mechanics that generate them. Determination of the in situ mechanical properties of ankle ligaments provides a better understanding of the nonlinear nature of the ankle joint. Applications of this knowledge include functional ankle joint mechanics and injury biomechanics.

Risk factors for lower leg, ankle and foot injuries during basic military training in the Maltese Armed Forces

OBJECTIVES

Basic military training is physically and psychologically demanding placing recruits at high risk of injury and premature discharge. This study aimed to identify risk factors for lower leg, ankle and foot injury in Maltese military recruits during basic training.

DESIGN

This was a prospective cohort study.

SETTING

An armed forces barracks.

PARTICIPANTS

127 recruits commencing one basic military training course agreed to participate in the study. The cohort comprised 114 males and 13 females with a mean age of 21.7 ± 2.4 years.

MAIN OUTCOME MEASURES

All injuries to the lower leg, ankle and foot were recorded using the Orchard Sports Injury Classification System. Injuries were analysed for associations with fitness scores, smoking status, body mass index and foot type.

RESULTS

A total of 34 (26.2%) recruits sustained at least one injury, with 10 recruits (7.9%) terminating their training prematurely (three due to musculoskeletal injury). Smoking history, body mass index and foot type were not associated with injury risk. Lower fitness levels at the commencement of basic military training compared with fitness levels measured six months prior, were associated with higher injury risk.

CONCLUSIONS

Lower fitness at the commencement of basic training was associated with higher injury risk in army recruits. Thus, conditioning programmes aimed at improving recruit fitness should be considered within an injury prevention strategy.

Foot and Ankle Injuries in Professional Soccer Players: Diagnosis, Treatment, and Expectations

Soccer is one of the most popular sports in the world. It has undergone many changes in recent years, mainly because of increased physical demands, and this has led to an increased injury risk. Direct contact accounts for half of all injuries in both indoor and outdoor soccer and ankle sprains are the most common foot and ankle injury. There is a spectrum of foot and ankle injuries and their treatment should be individualized in these high-demand patients. An injury prevention program is also important and should the players, the trainer, responsible physician, and physical therapists.

Peroneal tendinosis as a predisposing factor for the acute lateral ankle sprain in runners

PURPOSE

A painful episode in the region of the peroneal tendons, within the retromalleolar groove, is a common precipitating event of an acute lateral ankle sprain. A forefoot striking pattern is suspected to cause peroneal tendinosis. The aim of this study is to analyse the role of peroneal tendinosis as a predisposing factor for ankle sprain trauma in runners.

METHODS

Fifty-eight runners who had experienced acute ankle sprain trauma, with pre-existing pain episodes for up to 4 weeks in the region of the peroneal tendons, were assessed clinically. Fractures were excluded by conventional radiography. An magnetic resonance imaging (MRI) scan had been performed within 14 days after the traumatic event and was subsequently evaluated by two experienced radiologists.

RESULTS

MRI revealed peroneal tendinosis in 55 patients (95% of the total study population). Peroneus brevis (PB) tendinosis was found in 48 patients (87% of all patients with peroneal tendinosis), and peroneus longus (PL) tendinosis was observed in 42 cases (76%). Thirty-five patients (64%) had combined PB and PL tendinosis. A lesion of the anterior talofibular ligament was found to be the most common ligament injury associated with peroneal tendinosis (29 cases; 53%), followed by a lesion of the calcaneofibular ligament (16 cases; 29%) and a lesion of the posterior tibiofibular ligament (13 cases; 24%).

CONCLUSION

The results of this study reflect the correlation between peroneal tendinosis and ankle sprain trauma. Injuries of one or more ligaments are associated with further complications. A period of rest or forbearance of sports as well as adequate treatment of the peroneal tendinosis is essential to prevent subsequent ankle injuries, especially in runners. Modification of the running technique would also be beneficial.

LEVEL OF EVIDENCE

IV.

A framework for parametric modeling of ankle ligaments to determine the in situ response under gross foot motion

Ligament sprains account for a majority of injuries to the foot and ankle complex, but ligament properties have not been understood well due to the difficulties in replicating the complex geometry, in situ stress state, and non-uniformity of the strain. For a full investigation of the injury mechanism, it is essential to build up a foot and ankle model validated at the level of bony kinematics and ligament properties. This study developed a framework to parameterize the ligament response for determining the in situ stress state and heterogeneous force-elongation characteristics using a finite element ankle model. Nine major ankle ligaments and the interosseous membrane were modeled as discrete elements corresponding functionally to the ligamentous microstructure of collagen fibers and having parameterized toe region and stiffness at the fiber level. The range of the design variables in the ligament model was determined from existing experimental data. Sensitivity of the bony kinematics to each variable was investigated by design of experiment. The results highlighted the critical role of the length of the toe region of the ligamentous fibers on the bony kinematics with the cumulative influence of more than 95%, while the fiber stiffness was statistically insignificant with an influence of less than 1% under the given variable range and loading conditions. With the flexibility of variable adjustment and high computational efficiency, the presented ankle model was generic in nature so as to maximize its applicability to capture the individual ligament behaviors in future studies.

The role of the medial ligaments in lateral stabilization of the ankle joint: an in vitro study

PURPOSE

The deltoid ligament complex is known as medial stabilizer in the ankle against pronation/eversion. Lateral dual-ligament laxity often results in chronic ankle instability with recurring ankle sprain trauma. The goal of this study is to examine the lateral stabilizing role of the deltoid ligament complex against supination/inversion in case of existing lateral ligament instability.

METHODS

A torsion simulation was performed on 12 fresh human lower leg cadaver specimens in a loading frame and a specially designed mounting platform. The preset torsion between tibia and calcaneus was primarily set at 30° of internal rotation on specimen in plantar flexion and hindfoot inversion. The measured variable was the resisting torque recorded around mechanical tibial axis, which ensures stability in ankle sprain trauma. The first series of measurements were performed on healthy specimens and the following after transecting structures in following order: anterior talofibular ligament (ATFL) in combination with calcaneofibular ligament (CFL), followed by anterior tibiotalar ligament and posterior tibiotalar ligament and finally tibiocalcaneal ligament (TCL).

RESULTS

The combined lateral ATFL and CFL instability showed a decrease in the resisting torque, which ensures stability in ankle sprain trauma. Only a transection of TCL (superficial layer of deltoid ligament complex) with existing lateral dual-ligament instability results in a significant decrease in torque (p<0.0001).

CONCLUSION

The goal of the study was to provide the orthopaedic and/or trauma surgeon with quantitative data that may be referred to the substantial stabilizing effect of TCL against supination/inversion in the ankle joint in case of repetitive sprain trauma at a present lateral ligament lesion. Diagnostics of and treatment for lateral ligament instability need to consider the deltoid ligament complex,especially TCL in clinical routine.

Ankle instability and arthroscopic lateral ligament repair

Over the last 50 years, the surgical management of chronic lateral ankle ligament insufficiency has focused on 2 main categories: local soft-tissue reconstruction and tendon grafts/transfer procedures. There is an increasing interest in the arthroscopic solutions for chronic instability of the ankle. Recent biomechanical studies suggest the at least one of the arthroscopic techniques can provide equivalent results to current open local soft-tissue reconstruction (such as the modified Brostrom technique). Arthroscopic lateral ankle ligament reconstruction is becoming an increasingly acceptable method for the surgical management of chronic lateral ankle instability.

Efeito do treinamento proprioceptivo no equilíbrio de atletas de ginástica rítmica

INTRODUÇÃO: A ginástica rítmica (GR) é uma modalidade esportiva que combina arte a gestos biomecânicos de alta complexidade, que requer alto nível de desenvolvimento de qualidades físicas como: agilidade, flexibilidade, força, impulsão e destreza. Nessa modalidade, estudos comprovam que as lesões mais frequentes ocorrem nas articulações do joelho e tornozelo e, em alguns casos, nas extremidades do punho, sendo os entorses as mais registradas, principalmente em atletas de nível de competição. Diante disso, a propriocepção e o controle muscular possuem papel fundamental na estabilidade articular dinâmica, já que após lesões ortopédicas algumas características sensório-motoras são alteradas e devem ser o foco de programas de reabilitação para que se obtenha melhor retorno às atividades como antes da lesão.OBJETIVO: Avaliar o efeito do treinamento proprioceptivo sobre o equilíbrio postural de atletas de ginástica rítmica, a partir da utilização da plataforma de força.MÉTODOS: Foi realizado um treinamento proprioceptivo no período de 2 meses, subdividido em três fases, com progressão da complexidade dos exercícios a cada fase de treinamento.RESULTADOS: Podemos observar que houve uma melhora significativa dos resultados da última fase do treinamento, quando foram utilizados exercícios de maior complexidade e agilidade, de acordo com o protocolo.CONCLUSÃO: Por se tratarem de atletas de GR de alto desempenho e apresentarem predomínio de atividades em apoio unipodal, os protocolos de propriocepção devem ser mais intensos, gerando um maior nível de perturbações e desequilíbrios posturais.

Management of chronic lateral ankle instability in military service members

Chronic lateral ankle instability is a condition frequently encountered by orthopedic surgeons treating highly active patient populations, particularly military service members. Providers treating military service members must have a high index of suspicion for this condition when signs and symptoms of functional or mechanical instability exist. Stress testing and ankle MRI, although not definitive in sensitivity for detecting instability or other concomitant injuries, should be considered during the treatment decision-making process. Appropriate nonoperative treatment should be attempted initially; however, when nonoperative treatment fails, surgical management is warranted to prevent untoward long-term sequelae. Proper surgical treatment and subsequent postoperative management are at the discretion of the individual surgeon but must account for the concomitant diseases frequently associated with chronic lateral ankle instability. Low recurrence of lateral instability can be achieved even in high-demand military patient populations with a focused treatment plan.

Deltoid ligament in acute ankle injury: MR imaging analysis

OBJECTIVE

To identify the pattern of deltoid ligament injury after acute ankle injury and the relationship between ankle fracture and deltoid ligament tear by magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Thirty-six patients (32 male, and 4 female; mean age, 29.8 years) with acute deltoid ligament injury who had undergone MRI participated in this study. The deltoid ligament was classified as having 3 superficial and 2 deep components. An image analysis included the integrity and tear site of the deltoid ligament, and other associated injuries. Association between ankle fracture and deltoid ligament tear was assessed using Fisher's exact test (P < 0.05).

RESULTS

Of the 36 patients, 21 (58.3 %) had tears in the superficial and deep deltoid ligaments, 6 (16.7 %) in the superficial ligaments only, and 4 (11.1 %) in the deep ligaments only. The most common tear site of the three components of the superficial deltoid and deep anterior tibiotalar ligaments was their proximal attachments (94 % and 91.7 % respectively), and that of the deep posterior tibiotalar ligament (pTTL) was its distal attachment (82.6 %). The common associated injuries were ankle fracture (63.9 %), syndesmosis tear (55.6 %), and lateral collateral ligament complex tear (44.4 %). All the components of the deltoid ligament were frequently torn in patients with ankle fractures (tibionavicular ligament, P = 0.009).

CONCLUSION

The observed injury pattern of the deltoid ligament was complex and frequently associated with concomitant ankle pathology. The most common tear site of the superficial deltoid ligament was the medial malleolar attachment, whereas that of the deep pTTL was near its medial talar insertion.

An unusual cause of ankle pain: fracture of a talocalcaneal coalition as a differential diagnosis in an acute ankle sprain: a case report and literature review

BACKGROUND

The acute ankle sprain is one of the most common injuries seen in trauma departments. Ankle sprains have an incidence of about one injury per 10 000 people a day. In contrast tarsal coalition is a rare condition occurring in not more than one percent of the population.

CASE PRESENTATION

We present the case of a 23 year old male patient with pain and local swelling after an acute ankle sprain. Initial clinical and radiological examination showed no pathologies. Due to prolonged pain, swelling and the inability of the patient to weight bear one week after trauma further diagnostics was performed. Imaging studies (MRI and CT) revealed a fracture of a talocalcaneal coalition. To the knowledge of the authors no fracture of a coalition was reported so far.

CONCLUSION

This report highlights the presentation of symptomatic coalitions following trauma and furthermore, it points out the difficulties in the diagnosis and treatment of a rare entity after a common injury. A diagnostic algorithm has been developed to ensure not to miss a severe injury.

Evaluation of a modified Broström-Gould procedure for treatment of chronic lateral ankle instability: A retrospective study with critical analysis of outcome scoring

BACKGROUND

Chronic lateral ankle instability accounts for 20% of the ankle injuries. This study evaluates functional outcome of the modified Broström-Gould technique using suture anchors, with 4 different clinical scores.

METHODS

A consecutive series of 41 patients were included with a minimum follow-up of one year. The function was assessed using 4 clinical scores including: the AOFAS for hind foot; the FAAM; the CAIT and the CAIS.

RESULTS

Out of 41 patients; 27 patients were very satisfied, 11 satisfied and 3 were not satisfied. Ankle mobility returned to normal in 93% of patients. At follow-up the AOFAS was 89/100 (37-100), the FAAM 85/100% (35-100%), the CAIT 20/30 (5-30), and the CAIS 74/100% (27-100%).

CONCLUSION

Outcome of modified Broström-Gould procedure is good with high satisfaction rate in terms of ankle mobility. The disparity in outcome of scores, signals towards the need of a standard evaluation system.

The diagnosis and treatment of deltoid ligament lesions in supination-external rotation ankle fractures: a review

The supination–external rotation or Weber B type fracture exists as a stable and an unstable type. The unstable type has a medial malleolus fracture or deltoid ligament lesion in addition to a fibular fracture. The consensus is the unstable type and best treated by open reduction and internal fixation. The diagnostic process for a medial ligament lesion has been well investigated but there is no consensus as to the best method of assessment. The number of deltoid ruptures as a result of an external rotation mechanism is higher than previously believed. The derivation of the injury mechanism could provide information of the likely ligamentous lesion in several fracture patterns. The use of the Lauge-Hansen classification system in the assessment of the initial X-ray images can be helpful in predicting the involvement of the deltoid ligament but the reliability in terms of sensitivity and specificity is unknown. Clinical examination, stress radiography, magnetic resonance imaging, arthroscopy, and ultrasonography have been used to investigate medial collateral integrity in cases of ankle fractures. None of these has shown to possess the combination of being cost-effective, reliable and easy to use; currently gravity stress radiography is favoured and, in cases of doubt, arthroscopy could be of value. There is a disagreement as to the benefit of repair by suture of the deltoid ligament in cases of an acute rupture in combination with a lateral malleolar fracture. There is no evidence found for suturing but exploration is thought to be beneficial in case of interposition of medial structures.

Hindfoot joint pressure in supination sprains

BACKGROUND

Hindfoot trauma including ankle and subtalar sprains may be followed by osteochondral lesions and persisting pain originating from posttraumatic arthritis.

HYPOTHESIS

"Acute severe" supination sprains and "mild supination sprains with increasing ligamentous incompetence" of the hindfoot lead to medial ankle and subtalar stress concentrations that may contribute to osteochondral lesions (OCLs) and subsequent arthritis.

STUDY DESIGN

Controlled laboratory study.

METHODS

"Acute severe" sprains and "mild sprains with increasing ligamentous incompetence" (consecutive anterior talofibular ligament [ATFL], calcaneofibular ligament [CFL], and lateral talocalcaneal ligament [LTCL] transections) were simulated in human lower leg specimens (7 different specimens for each condition). The effect on the migration of the center of force (COF) and on the tibiotalar and subtalar pressures at 700-N (acute severe) and 150-N (mild sprain with increasing ligamentous incompetence) axial static and dynamic loads, respectively, was recorded using pressure sensors.

RESULTS

In the "acute severe" sprain, the peak pressure increase reached the level of significance in the ankle (P = .042) and in the subtalar medial facet (P = .046). The ankle COF migrated significantly toward the medial (P = .001) and posterior (P = .023) directions. In the "mild sprain with increasing ligamentous incompetence" condition, the ankle (P = .018) and subtalar (medial facet, P = .022) peak pressure increased significantly with intact ligaments and with all ligaments cut. The ankle COF migrated significantly toward the medial direction when the ATFL and CFL or when all 3 ligaments were severed. The anteroposterior ankle COF migration was anterior when all ligaments were intact or when only the ATFL was severed but posterior when the CFL or when the CFL and the LTCL were severed in addition.

CONCLUSION

Next to chronic inhomogeneous load distribution in the unstable hindfoot and shear stress during sprains, intra-articular pressure elevation (impact) in the ankle and subtalar joint during hindfoot supination sprains with intact ligaments or incompetent ligaments likely contributes to OCLs of the medial talar dome and the medial subtalar facet.

CLINICAL RELEVANCE

Intra-articular hindfoot pressure elevation (impact) in "acute severe" and in "mild hindfoot supination sprains with increasing ligamentous incompetence" is substantial for the development of OCLs at the medial midtalar dome and the medial facet of the subtalar joint.

Functional performance testing in athletes with functional ankle instability

PURPOSE

To determine if functional performance deficits are present in athletes with functional ankle instability (FAI) compared to healthy athletes using various functional performance tests.

METHODS

Sixty two athletes (mean age-21.7±1.8years; height-168.2±9.1cm; weight-63.8±11.0kg) participated in this case control study. Athletes were divided into two groups: athletes with FAI (FAI group, n=31) and healthy athletes (Non-FAI group, n=31). The FAI group was further divided into two subgroups: FAI with giving way (FAI-GW), FAI with no giving way (FAI-NGW). Functional performance was assessed with the single-limb hopping test, figure-of-8 hop test, side-hop test, single-limb hurdle test, square hop test and single hop test.

RESULTS

Significant differences (P<0.05) were observed for all the functional performance tests (FPTs) except the single hop test between FAI and Non-FAI groups; between FAI-GW, FAI-NGW and Non-FAI groups. Additionally, the involved limb performed significantly worse (P<0.05) than the contra-lateral uninvolved limb of the FAI-GW group for the above-mentioned FPTs.

CONCLUSION

Significant functional performance deficits were observed in the FAI group in all tests except single hop test with greater deficits observed in the FAI-GW group. Hence, these tests can be used to determine the presence of FAI. However no deficits were identified for the test involving sagittal plane functional activities suggesting that this test can not be used as a criterion to discriminate individuals with FAI. It was further ascertained that functional performance was not affected by limb dominance.

Deltoid ligament abnormalities in chronic lateral ankle instability

BACKGROUND

Treatment of patients with repeated ankle sprains and chronic lateral ankle instability tends to focus on the lateral collateral ligaments. We reviewed records to ascertain the prevalence of abnormalities of the deltoid ligament in this population.

METHODS

Retrospective review of MR images and surgical reports was performed for all patients during a 3-year period that underwent surgical treatment of chronic ankle instability at a single institution. Forty-seven ankles (46 patients) met inclusion criteria. None had medial ankle pain.

RESULTS

On MRI, all patients had anterior talofibular ligament tear, plus injury to one or more additional ligaments. Ninety-one percent had injury of calcaneofibular ligament. Injury to the posterior talofibular ligament was less common (49%). Deltoid ligament injuries were seen in 72% of cases (23% superficial deltoid only, 6% deep deltoid only, 43% both superficial and deep components). Of patients with injury to the superficial deltoid, 32% had an intact deep deltoid ligament. MRI correlated well to surgical findings.

CONCLUSION

Deltoid ligament injuries were common in patients with lateral ankle instability who underwent reconstruction.

Chronic ankle instability: evolution of the model

CONTEXT

The Hertel model of chronic ankle instability (CAI) is commonly used in research but may not be sufficiently comprehensive. Mechanical instability and functional instability are considered part of a continuum, and recurrent sprain occurs when both conditions are present. A modification of the Hertel model is proposed whereby these 3 components can exist independently or in combination.

OBJECTIVE

To examine the fit of data from people with CAI to 2 CAI models and to explore whether the different subgroups display impairments when compared with a control group.

DESIGN

Cross-sectional study.

PATIENTS OR OTHER PARTICIPANTS

Community-dwelling adults and adolescent dancers were recruited: 137 ankles with ankle sprain for objective 1 and 81 with CAI and 43 controls for objective 2.

INTERVENTION(S)

Two balance tasks and time to recover from an inversion perturbation were assessed to determine if the subgroups demonstrated impairments when compared with a control group (objective 2).

MAIN OUTCOME MEASURE(S)

For objective 1 (fit to the 2 models), outcomes were Cumberland Ankle Instability Tool score, anterior drawer test results, and number of sprains. For objective 2, outcomes were 2 balance tasks (number of foot lifts in 30 seconds, ability to balance on the ball of the foot) and time to recover from an inversion perturbation. The Cohen d was calculated to compare each subgroup with the control group.

RESULTS

A total of 56.5% of ankles (n = 61) fit the Hertel model, whereas all ankles (n = 108) fit the proposed model. In the proposed model, 42.6% of ankles were classified as perceived instability, 30.5% as recurrent sprain and perceived instability, and 26.9% as among the remaining groups. All CAI subgroups performed more poorly on the balance and inversion-perturbation tasks than the control group. Subgroups with perceived instability had greater impairment in single-leg stance, whereas participants with recurrent sprain performed more poorly than the other subgroups when balancing on the ball of the foot. Only individuals with hypomobility appeared unimpaired when recovering from an inversion perturbation.

CONCLUSIONS

The new model of CAI is supported by the available data. Perceived instability alone and in combination characterized the majority of participants. Several impairments distinguished the sprain groups from the control group.

The effects of multiaxial and uniaxial unstable surface balance training in college athletes

The purpose of this study was to compare the effects of 2 different types of unstable surface balance training (uniaxial on a rocker board [RB] and multiaxial on a dynadisc [DD]) on balance in division 1 collegiate athletes in sports that are at high risk for ankle sprains. Subjects (n = 36) consisted of male soccer players and female volleyball and soccer players who were equally and randomly assigned to 1 of 3 groups (CON, DD, and RB). Balance training consisting of balancing on 1 leg on either the RB or DD, while repeatedly catching a 1-kg ball was performed 3 times per week for 4 weeks. Balance was tested with the Star Excursion Balance Test (SEBT) before, halfway through, and at the completion of the balance training. Control (CON) subjects also were given the balance test but did not participate in the training. A 3-way repeated analysis of variance revealed that no group individually changed SEBT scores from pre (CON, 0.98 +/- 0.086; DD, 0.98 +/- 0.083; RB, 0.97 +/- 0.085) to post (CON, 1.00 +/- 0.090; DD, 1.01 +/- 0.088; RB, 1.02 +/- 0.068) after balance training. When the 2 treatment groups were combined (DD and RB), the p value decreased and came closer to significance (p = 0.136). When all 3 groups were combined, there was a significant difference in SEBT scores from pretraining (CON + DD + RB; 0.98 +/- 0.085) to posttraining (CON + DD + RB; 1.01 +/- 0.082), which likely indicates low statistical power. The increase in physical activity the subjects experienced during the return to in-season activity, may have contributed to the significant differences in SEBT scores over time but not between DD or RB training. Therefore, a threshold level of physical activity may exist that is necessary to maintain balance during the off-season.

MR imaging of deltoid ligament pathologic findings and associated impingement syndromes

Injuries of the deltoid ligament of the ankle are increasingly recognized with the widespread use of magnetic resonance (MR) imaging. The use of higher magnetic field strengths requires familiarity with the anatomic substructure of the deltoid ligament to better localize and characterize pathologic findings. Specifically, improved image resolution allows components of the superficial (tibiocalcaneal, tibionavicular, posterior superficial tibiotalar, and tibiospring ligaments) and deep (anterior tibiotalar and posterior deep tibiotalar ligaments) portions of the ligament to be evaluated separately. Awareness of the deltoid ligament substructure and associated injury patterns can guide the radiologist in defining underlying mechanical derangement, such as that seen in various impingement disorders. In this review article, the MR imaging technique for the deltoid ligament is summarized, and the normal and abnormal MR imaging appearances of various components of the deltoid ligament and associated impingement syndromes are presented.

Side-to-side difference in joint position sense and kinesthesia in unilateral functional ankle instability

BACKGROUND

Impairment in proprioception has been suggested to be one of the causes of FAI. This study aimed to establish intra-session reliability of the Biodex System 2 in assessing joint position sense (JPS) and kinesthesia (K)~in addition to determining if there was any side to side difference in JPS and kinesthesia in people with unilateral functional ankle instability.

MATERIALS AND METHODS

Both JPS and K were determined by means of the Biodex Systems 2. During evaluation of JPS, participants' ability to actively reproduce ankle joint position was tested three times in each of the two predetermined positions. During evaluation of K, data collection began with the foot placed in a starting position of 0 degrees (neutral position).

RESULTS

A total of 25 participants (mean age 22.0 years, 95% confidence interval 19.9 to 24.1 years) were recruited into this study. No difference in JPS (p = 0.162 to 0.764) and K (p = 0.089 to 0.683) were found between the sprained and uninvolved ankle of subjects with unilateral functional ankle instability. There is moderate to good intra-session reliability in using the Biodex System 2 to assess JPS (ICC = 0.868 to 0.950, p < 0.01) and K (ICC = 0.825 to 0.893, p < 0.01).

CONCLUSION

This study suggests that there is perhaps no difference in JPS and K between both ankles in people with unilateral FAI. Proprioceptive deficits may not always be present in every case of FAI.

CLINICAL RELEVANCE

Proprioceptive training may not be beneficial in some patients with unilateral FAI.

The role of shoe design in ankle sprain rates among collegiate basketball players

CONTEXT

Much of the recent focus in shoe design and engineering has been on improving athletic performance. Currently, this improvement has been in the form of "cushioned column systems," which are spring-like in design and located under the heel of the shoe in place of a conventional heel counter. Concerns have been raised about whether this design alteration has increased the incidence of ankle sprains.

OBJECTIVE

To examine the incidence of lateral ankle sprains in collegiate basketball players with regard to shoe design.

DESIGN

Prospective cohort study.

SETTING

Certified athletic trainers at 1014 National Collegiate Athletic Association (NCAA)-affiliated schools sponsoring basketball during the 2005-2006 regular season were notified of an online questionnaire. Athletic trainers at 22 of the 1014 schools participated.

PATIENTS OR OTHER PARTICIPANTS

A total of 230 basketball players (141 males, 89 females; age = 20.2 +/- 1.5 years) from NCAA Division I-III basketball programs sustained lateral ankle sprains.

MAIN OUTCOME MEASURE(S)

Ankle sprain information and type of shoe worn (cushioned column or noncushioned column) were collected via online survey. The incidence of lateral ankle sprains and type of shoes worn were compared using a chi-square analysis.

RESULTS

No difference was noted in ankle sprain incidence between groups (chi(2) = 2.44, P = .20, relative risk = 1.47, 95% confidence interval [CI] = 0.32, 6.86). The incidence of ankle sprains was 1.33 per 1000 exposures in the cushioned column group (95% CI = 0.62, 3.51) and 1.96 per 1000 exposures in the noncushioned column group (95% CI = 0.51, 4.22).

CONCLUSIONS

No increased incidence of ankle sprains was associated with shoe design.