Introduction
The distal tibiofibular joint is described as a syndesmosis. It comprises the tibia and fibula, the fibrous interosseous membrane (IOM) between the two bones, the anterior inferior tibiofibular ligament (AITFL), posterior inferior tibiofibular ligament (PITFL), transverse ligament (TL) and the interosseous ligament (IOL) .1 While syndesmotic injuries are described as disruption to one or more of the ligaments,1 they often occur in conjunction with ankle fractures 13%–50% of the time.2 3
Syndesmosis injuries, or ‘high ankle sprains’, are relatively uncommon making up between 1% and 18% of ankle ligament injuries.1 4 5 This large variation might indicate an under-reporting of these injuries,6 reflecting the difficulty identifying syndesmotic ligament damage.6 Sporting populations are more likely to suffer from syndesmotic injuries due to the forces required to damage the ligaments.6 7 Injuries are commonly sustained during activities that involve a cutting motion, or following a forced external rotation movement on a fixed foot as can occur during contact sports.5 8 9
Syndesmotic injuries are consistently associated with higher levels of disability, pain and prolonged periods out of sporting participation.10–12 They have also been described as one of the most difficult sporting injuries to treat,6 with rehabilitation potentially taking between twice and 30 times longer than isolated lateral ligament sprains.13
Traditionally, higher grade syndesmotic injuries have been treated surgically with screw fixation being the most common method used (75% of the time).14 This poses problems for the athletic population as the screw requires removal (68% of the time) between 3 and 6 months post fixation, potentially delaying rehabilitation and return to sport.15 Screw fixation can lead to malreduction in up to 39% of cases,16 causing chronic instability and symptoms. An unstable syndesmosis injury requiring surgical fixation will commonly require 4–6 months before successful return to sport.17
A novel surgical approach to syndesmosis repair has been developed involving a tightrope procedure.18–20 This involves implanting two to four cortical endobuttons and looping a non-absorbable suture around them to provide semirigid fixation.21 22 Theoretically, it has a number of advantages over traditional screw fixation: it allows for a small amount of normal biomechanical movement at the syndesmosis; it rarely requires a second operation to remove the device; it provides significantly better anatomic reduction and it allows for earlier return to weight-bearing, rehabilitation and ultimately sport.7 21 23–25
Rehabilitation following surgery, via either screw fixation or tightrope repair is controversial with little consensus as to the optimal regimen.7 Most regimen consist of a period of immobilisation and restricted weight-bearing, progressing to restoration of range of movement, strength and proprioception, finally sports-specific drills prior to return to competition.7 26 The exact make-up of each rehabilitation regimen differs from study to study attributed to the differing functional needs of individuals, their sporting requirements and the postsurgical protocol implemented by the surgeons.
This case series will detail an ankle syndesmosis tightrope repair and an accelerated rehabilitation protocol that significantly reduces the amount of time before return to professional rugby league in the UK is possible.
To ensure methodological rigour for the reporting of this case series report, the CARE (CAse REport consensus-based guidelines) guidelines were followed.27
Patient information
From January 2010 to September 2015, 18 adult men playing full-time professional rugby league from six different Rugby Football League (RFL) Super league clubs were identified with ankle syndesmosis injuries. Average age at the time of injury was 22 years (SD 3.3, range 17–28). Players had no current or past medical report of note and their main complaint was pain, instability and reduced ability to weight bear in the affected ankle.
Players were identified via a single orthopaedic surgeon in the UK specialising in ankle syndesmosis repair. Ethical approval for the current study was obtained from Manchester Metropolitan University. An information sheet and consent form was issued to each player detailing the current study and its aims.
Mechanism of injury, diagnostic work-up, exact surgical procedure, rehabilitation protocol followed and any adverse events data were collected. Data were collected from the therapy notes by an independent researcher (AJL). The treating physiotherapy team were contacted to complete any omissions in the notes and to ensure accuracy of data collected.
The most common mechanism of injury reported was forced dorsiflexion/eversion (n=8), isolated eversion (n=2), forced rotation (n=2), forced plantar flexion/inversion (n=3), insidious (n=2) and one incident of forced plantar flexion accounted for the remaining cases. One player injured both ankles in separate incidents 5 months apart, otherwise all were first-time injuries.
Diagnosis
Mean time from injury to diagnosis was 21 days (SD 54.7, range 0–210). Results were skewed by two atypical cases not being diagnosed for 3 and 7 months, respectively. Two further cases were managed conservatively for 2 weeks before diagnostic testing was initiated. With these omitted mean time from injury to diagnosis was 1.8 days (SD 2.2, range 0–7). Diagnosis was based on MRI confirmed diastasis and a physical examination by the treating surgeon.
Criteria for surgical intervention in 16 of the 18 cases was based on MRI-confirmed diastasis in keeping with the grading suggested by Sikka et al 28 and a surgeon-led approach. In the other two cases, weight-bearing X-ray confirmed diastasis and physical examination findings were the criteria for surgery.
Surgical intervention
Average time from injury to surgery was 38.7 days (SD 73.7, range 2–265), skewed by the two atypical results. Omitting these cases, mean time from injury to surgery was 13.7 days (SD 8.73 range 2–31). Mean time from diagnosis to surgery for the group was 10 days (SD 7 range 2–22).
All players underwent a double tightrope repair performed by the same surgeon. This involved a lateral incision to provide access to the distal fibula. A 3.5 mm drill bit was passed through all four cortices of the tibia and fibula before being removed and the medial endobutton was passed through the predrilled hole using a needle. Once through the medial tibial cortex, the guide sutures were used to orientate the oblong medial endobutton so that it sat perpendicular to the hole flush with the bone. Arthrex TightRope (Arthrex, Naples, Florida, USA) No. 5 FiberWire (Arthrex) made of ultra-high molecular weight polyethylene anchored two metallic cortical buttons to provide physiological stabilisation of the ankle mortise (figure 1). The lateral, round endobutton was then tightened to reduce the syndesmosis and ensure the fibula sat in the fibula notch and the button sat flush with the fibula bones’ outer cortex. A second tightrope was then passed in the same way to improve the stability and strength of the repair (figure 1).
Syndesmosis tightrope repair. (Picture courtesy of Laura Latham, March 2016.)
Four players had a concurrent anterior talofibular ligament (ATFL) repair and one player required an open reduction internal fixation (ORIF) of the fibula. For the patient with the fractured fibula, the fracture was stabilised first using internal fixation with a plate. The tightropes were then placed through two of the empty screw holes with the lateral round endobuttons sitting flush in the screw hole recesses on the lateral side.
Physiotherapy intervention
Fourteen out of 18 players followed the same postoperative protocol, progressed by the treating physiotherapist depending on pain, swelling and of range of movement (ROM). Of the remaining four players, three followed an altered protocol because of them not having access to an AlterG antigravity treadmill (Alter-G, Fremont, California, USA). The final player had a fibula ORIF, which delayed his rehabilitation.
Home exercises were given from week 2 onwards, mirroring progression in the protocol and to supplement daily physiotherapy sessions. Authors AB and BS developed the protocol using the double tightrope repair’s ability to progress rehabilitation faster than a traditional screw fixation would allow.
Week 1
This period included 5 days in a plaster-of-paris (POP) boot postoperatively and 3 weeks in an Aircast boot (DJO Global, Vista, California, USA), progressively increasing weight-bearing as pain and swelling allowed. The Aircast boot was removed for physiotherapy.
Weeks 2 to 4
The Protection, Rest, Ice, Compression and Elevation (PRICE) principles were followed every 2 hours to reduce swelling and alleviate pain.16 The boot was removed for ankle ROM exercises in the sagittal plane only to avoid stressing the repair. Isometric strengthening exercises in plantar grade and foot intrinsic muscle exercises were performed. Proprioception exercises with the boot on and non-weight-bearing exercises to maintain the larger lower limb muscles (gluteals, quadriceps and hamstrings) began.
Weeks 3 to 4
The boot was removed to allow static bike use as pain allowed. Ankle ROM exercises in all directions (with caution not to force the movement) and isotonic strengthening in the sagittal plane from plantar grade into plantar flexion were also commenced. The PRICE regimen continued every 2 hours.
Week 4
Following surgical review, the boot was removed and players allowed to run using an AlterG antigravity treadmill at 50% of body weight providing they were within 2 cm of their preinjury knee to wall test scores. This was progressed individually according to pain, swelling and restoration of ankle dorsiflexion.
Week 5
Ankle ROM exercises in all directions were progressed into stiffness with caution not to push into combined dorsiflexion and eversion; this maximally stresses the ankle mortise and the repair.26 Manual therapy directed to the superior tibiofibular joint, midfoot and tarsal bones was introduced if necessary.
Week 6
Exercises were progressed into full weight-bearing with land-based running replacing the use of AlterG antigravity treadmill. Global strengthening of the lower limb in weight-bearing commenced, good hip extension control was encouraged before advancing running.29 Subtalar joint mobilisations commenced for appropriate patients, and ROM was pushed into all directions specifically into restricted ranges.
Week 7
This week included sports-specific running drills, with functional and plyometric exercises. Multiplane exercises to improve ROM and ballistic proprioception training were progressed. Manual therapy to the talocrural joint were added to improve dorsiflexion as necessary.30 PRICE was encouraged after every training session and after home exercises.
Return to participation (RTP) decisions were made by the physiotherapist. The definition of RTP was return to full participation in training and match play.31 It was based on the criteria: ankle dorsiflexion back to pre-injury level (as per preseason testing or compared with uninjured ankle) or 2 cm or less on the knee to wall test32; symmetrical lower limb muscle strength; the ability to perform a symmetrical single leg hop for height and length and the ability to perform the star excursion balance test to pre-injury levels.31 33
Three players followed a modified postoperative rehabilitation as they did not have access to an AlterG antigravity treadmill. They were allowed to perform pain-free partial weight-bearing from the outset. The Aircast boot was removed when the subject reported mobilising full weight-bearing, pain free for a whole week. They waited until they could perform a pain-free heel raise, lunge and hop prior to returning to land-based running (two subjects started at 4 weeks with the other waiting until 7 weeks). This did not affect their RTP (mean=59 days, SD 12, range 48–72).
One player, due to a fibula ORIF, spent 6 weeks non-weight-bearing in a POP followed by 4 weeks in an Aircast boot. He began running at 50% body weight on an AlterG antigravity treadmill from 7 weeks and then followed the usual rehabilitation.
Eleven subjects (61%) regained full ROM prereturn to sport while seven subjects (39%) returned to sport prior to regaining full ROM. This suggests restoration of full ROM is not essential for return to competitive sport and training; this is common in syndesmotic injuries as up to 36% of cases can have persistent stiffness following injury.26
Follow-up
The average RTP for the whole group was 64 days (SD 17.2, range 38–108). A concomitant ATFL repair did not slow RTP (64 days). The player requiring an ORIF took longer to return to play (108 days RTP). Omitting this players’ data, the RTP average for the group reduces to 61.4 days.
Player complaints included: scar infections (n=2); persistent ankle stiffness (n=2); posterior calf tightness (n=1), hip pain (n=1) on return to running; and medial button site irritation (n=1), a problem previously reported in the literature for this procedure.21 This player required a guided corticosteroid injection 6 weeks postoperatively, returning to sport after 65 days.
One player did not adhere to his weight-bearing status early in his rehabilitation. This required counselling from the surgeon and a further week in the Aircast boot, subsequently delaying partial weight-bearing running from starting. This did not delay the player’s overall RTP time of 68 days.
