Pulley rupture and reconstruction in rock climbers

A4 Pulley Reconstruction Using the Superficialis Oblique Flap and the Transverse Double Loop Techniques: A Biomechanical Evaluation Using a Chicken Model

BACKGROUND

The pulley system plays an important role in flexion mechanism. Reconstruction after trauma can be challenging. Numerous techniques have been described with several drawbacks. Herein, we describe the superficialis flap oblique technique for A4 pulley reconstruction using an animal model.

METHODS

Forty-two fresh legs of 21 eight-week-old chickens were used to evaluate the maximum flexion angle (MFA) and force at maximum flexion (FMF) in intact and sectioned A4 pulley equivalents of the third digit after reconstruction with the transverse double loop (TDL) technique and the superficialis oblique flap (SOF) technique. Biomechanical measurements were obtained in an exclusively designed instrument. Descriptive statistics were reported, and mean differences between the reconstructive techniques were analyzed.

RESULTS

Intact and severed A4 pulley equivalent average MFA were 96.50° ± 1.70° and 115.60° ± 1.50°, respectively. Average FMF were 8.16 ± 0.23 psi with the intact pulley and 6.92 ± 0.20 psi with the sectioned pulley (P < 0.001). After reconstruction with TDL and SOF techniques, the legs reached an average MFA at the distal interphalangeal joint of 98.13° ± 1.20° and 96.90° ± 1.30°, respectively. Mean MFA difference was 1.23° (P = 0.03). Force at maximum flexion was 8.12 psi and 8.10 psi for the TDL and SOF techniques (P = 0.6), respectively.

CONCLUSIONS

The authors believe that SOF technique for A4 pulley reconstruction can be used as first option when available, taking into account its theoretical advantages and its proven biomechanical characteristics. Long-term functional results should be assessed to translate these results into the clinical setting.

Evaluation of A2 and A4 Hand Pulley Repair Using Tendon Graft Rings

PURPOSE

To compare the mechanical characteristics of A2 and combined A2-A4 pulley repair in the intact and damaged flexor pulley system.

METHODS

After control testing, we recorded tendon excursion and flexion of 11 cadaveric fingers after several interventions: (1) complete excision of A2 and A4, (2) repair of the A2 with one ring of tendon graft, (3) repair of the A2 with 2 rings of tendon graft, and (4) repair of the A2 with 2 rings combined with repair the A4 with one ring.

RESULTS

At the proximal interphalangeal (PIP) joint, the maximum rotational angle decreased by an average of 30% after complete excision of the A2 and A4 pulleys. This angle was still decreased compared with the control by an average of 25% after one-ring repair at A2, 23% after 2-ring repair at A2, and 17% after 2-ring repair at A2 combined with one-ring repair at A4. At the metacarpophalangeal joint, the average maximum rotational angle decreased by an average of 17% after complete excision of the A2 and A4 pulleys. This angle was still decreased compared with the control by an average of 11% after one-ring repair at A2, 7% after 2-ring repair at A2, and 4% after 2-ring repair at A2 combined with one-ring repair at A4. Kinematic behavior at the PIP joint with an intact pulley system was most closely approximated by the 3-loop repair. The least similar behavior was with a 2-ring construct at A2.

CONCLUSIONS

All repairs increased average flexion at the PIP and metacarpophalangeal joints compared with the unrepaired samples. The 3-ring configuration exhibited a higher recovery of PIP flexion compared with the other repairs.

CLINICAL RELEVANCE

Although each repair restored flexion, clinical studies are necessary to evaluate the clinical relevance of the mechanical results of this study.

Finger Flexor Pulley Injuries in Rock Climbers

Finger flexor pulley system injuries are the most common overuse injury in rock climbers. These injuries occur rarely outside of rock climbing, owing to the sport's unique biomechanical demands on the finger. As rock climbing continues to grow and earn recognition as a mainstream sport, an understanding of how to diagnose and treat these injuries also has become important. Our purpose is to describe current concepts in anatomy, biomechanics, clinical evaluation, imaging, prevention, and treatment strategies relating to finger flexor pulley system injuries. Our literature search was performed on PubMed with MeSH terms and keywords as subject headings to meet the objectives of this review. The "crimp grip" used in rock climbing is the mechanism for these injuries. The A2, A3, and A4 pulleys are at the highest risk of injury, especially when loaded eccentrically. Physical examination may reveal clinical "bowstringing," defined as the volar displacement of the flexor tendons from the phalanges; however, imaging is required for characterization of the underlying injury. Ultrasound is highly sensitive and specific for diagnosis and is recommended as the initial imaging technique of choice. Magnetic resonance imaging is recommended as an additional imaging study if ultrasound is inconclusive. Properly warming up increases the amount of physiologic bowstringing and is thought to prevent injury from occurring. Pulley injuries may be classified as grade I through IV. Conservative treatment, including immobilization, the H-tape method, and the use of a protective pulley splint, is recommended for grade I to III injuries. Surgical repair is reserved for grade IV injuries that are not amenable to conservative treatment.

Closed Traumatic A2 Through A4 Pulley Rupture and Flexor Digitorum Superficialis Avulsion Treated With Reconstruction

Background: Multiple closed spontaneous pulley ruptures are rare injuries and require surgical reconstruction to prevent functional deficits. Pulley rupture combined with avulsion of the flexor digitorum superficialis (FDS) tendon is an even more uncommon occurrence.

Case Report: We describe a closed traumatic annular 2 (A2) through annular 4 (A4) pulley rupture with avulsion of the FDS tendon. This uniquely associated pathology was treated with a complex surgical reconstruction that corrected flexion contracture and tendon bowstringing in the left long finger. The desired outcome was achieved through A2 and A4 pulley reconstruction using an autologous palmaris longus tendon graft with FDS tendon excision and proximal interphalangeal joint capsulotomy.

Conclusion: Multiple pulley rupture is not commonly combined with FDS avulsion, and treatment of this injury requires careful surgical planning based on pulley biomechanics to maximize postoperative function.

Olympic competition climbing: the beginning of a new era-a narrative review

Climbing as a competition sport has become increasingly popular in recent years, particularly the sub-discipline of bouldering. The sport will debut in the Tokyo Summer Olympic Games. National and international competitions have three disciplines: lead (climbing with rope protection), bouldering (climbing at lower heights with mattress floor protection) and speed (maximum speed climbing on a standardised route in 1-on-1 mode). There is also a 'combined mode' of all three disciplines (combined) which forms the Olympic competition format; all competition formats are held on artificial walls. Existing literature describes a predominantly low injury frequency and severity in elite climbing. In comparison to climbing on real rock, artificial climbing walls have recently been associated with higher injury rates. Finger injuries such as tenosynovitis, pulley lesions and growth plate injuries are the most common injuries. As finger injuries are sport-specific, medical supervision of climbing athletes requires specific medical knowledge for diagnosis and treatment. There is so far little evidence on effective injury prevention measures in top athletes, and antidoping measures, in general, requiring further work in this field. An improved data situation regarding high-performance climbing athletes is crucial to ensure that the sport continues to be largely safe and injury-free and to prevent doping cases as extensively as possible.

Feasibility of Homodigital Flexor Digitorum Superficialis transposition, a new technique for A2-C1 pulleys reconstruction: A kinematic cadaver study

INTRODUCTION

Homodigital flexor digitorum superficialis transposition (HFT) is proposed as a new technique for A2-C1 pulley reconstruction. Flexor digitorum superficialis is transposed on the proximal phalanx and inserted on the pulley rims, crossing over flexor digitorum profundus and acting as a pulley.

MATERIALS AND METHODS

The kinematic feasibility was investigated in a cadaveric bowstring model (after A2 and C1 pulley removal) on 22 fingers (thumb excluded).

RESULTS

HFT was effective in restoring the correct flexion of proximal and distal interphalangeal joints, compared to bowstring model. No adverse events were registered.

CONCLUSION

HFT is a feasible technique. Clinical application is encouraged.

Zone 2 Flexor Tendon Repair Location and Risk of Catching on the A2 Pulley

PURPOSE

To determine the region of the flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS) tendons in zone 2 that, when involved by a laceration repair, will reliably catch on the A2 pulley after surgery.

METHODS

Using fresh-frozen cadavers (5 hands, 20 digits), excursions of the FDP and FDS tendons were measured in relation to the A2 pulley. The C1, A3, and C2 pulleys were resected. The digit was maximally flexed by applying traction to the flexor tendon in the forearm. An 8-0 suture tag was placed in the flexor tendons immediately distal to the A2 pulley. The digit was then passively fully extended to measure tendon excursion. Measurements were repeated with 50% venting and 100% release of the A4 pulley. Reference points such as tendon insertions and flexion creases were obtained. This protocol was repeated sequentially for the index, middle, ring, and little fingers.

RESULTS

For all 20 fingers, the suture placed into the FDP just distal to the A2 pulley with the finger fully flexed traveled 1.6 ± 1.9 mm distal to the proximal edge of the A4 pulley with passive extension of the finger. The mean excursion for the FDP was 24.6 ± 3.2 mm, and 16.9 ± 3.1 mm for the FDS. The mean A2 pulley length was 16.2 ± 3.5 mm, and the mean distance between the distal edge of the A2 pulley and the proximal edge of the A4 pulley was 23.0 ± 3.3 mm. Venting the A4 pulley 50% and 100% increased FDP excursion a maximum of 0.9 and 1.9 mm, respectively.

CONCLUSIONS

An FDP repair proximal to the A4 pulley will slide under the A2 pulley with full active digital flexion after surgery. If the distal FDP stump lies underneath the A4 pulley with the digit fully extended, the FDP repair will not likely engage the A2 pulley with full flexion after surgery. The FDP excursion can be reliably predicted as a percentage of the A2 (distal) to the A4 (distal) pulley distance. Most importantly, the distance between the repair site and the A4 pulley approximately equals the length of the A2 pulley that requires release to avoid postoperative triggering.

CLINICAL RELEVANCE

Knowledge of this high-risk region of flexor tendon repair will guide surgeons regarding the potential need for partial release of the A2 pulley.

Anatomic Considerations and Reconstruction of the Thumb Flexor Pulley System

Disruption to the flexor pulley system of the thumb is an infrequent but devastating injury that can lead to significant compromise in both strength and function. Acute rupture leads to pain, weakness, reduced range of motion (ROM), and potential bowstringing of the flexor tendons. Conservative treatment with a pulley ring should be considered in all patients. However, failure of conservative treatment and bowstringing of the thumb are indications for operative intervention. Reconstruction of the oblique pulley system can be performed either in situ or using a free palmaris longus graft. Care should be taken to identify the neurovascular bundles to avoid compression during the reconstruction. Conscious sedation protocols augmented by ultrasound-guided sheath blocks allow the patient to actively and strongly contract the flexor pollicis longus tendon intraoperatively to appropriately tension the construct for optimal results. Rehabilitation should be performed in a stepwise manner beginning with early passive ROM, active ROM, and finally strengthening at around 8 weeks postoperative.

Acute A4 Pulley Reconstruction with a First Extensor Compartment Onlay Graft

Background:

The integrity of the flexor tendon pulley apparatus is crucial for unimpaired function of the digits. Although secondary reconstruction is an established procedure in multi-pulley injuries, acute reconstruction of isolated, closed pulley ruptures is a rare occurrence. There are 3 factors influencing the functional outcome of a reconstruction: gapping distance between tendon and bone (E-space), bulkiness of the reconstruction, and stability. As direct repair is rarely done, grafts are used to reinforce the pulley. An advantage of the first extensor retinaculum graft is the synovial coating providing the possibility to be used both as a direct graft with synovial coating or as an onlay graft after removal of the synovia when the native synovial layer is present.

Methods:

A graft from the first dorsal extensor compartment is used as an onlay graft to reinforce the sutured A4 pulley. This technique allows reconstruction of the original dimensions of the pulley system while stability is ensured by anchoring the onlay graft to the bony insertions of the pulley.

Results:

Anatomical reconstruction can be achieved with this method. The measured E-space remained 0 mm throughout the recovery, while the graft incorporated as a slim reinforcement of the pulley, displaying no bulkiness.

Conclusions:

The ideal reconstruction should provide synovial coating and sufficient strength with minimal bulk. Early reconstruction using an onlay graft offers these options. The native synovial lining is preserved and the graft is used to reinforce the pulley.

Diagnosis of Complex Pulley Ruptures Using Ultrasound in Cadaver Models

Pulley ruptures are common in climbing athletes. The purposes of this study were to determine the specific positioning of each pulley with regards to the joint, and to evaluate the ultrasound diagnostics of various pulley rupture combinations. For this, 34 cadaver fingers were analyzed via ultrasound, the results of which were compared to anatomic measurements. Different pulley ruptures were then simulated and evaluated using ultrasound in standardized dynamic forced flexion. Visualization of the A2 and A4 pulleys was achieved 100% of the time, while the A3 pulley was visible in 74% of cases. Similarly, injuries to the A2 and A4 pulleys were readily observable, while A3 pulley injuries were more challenging to identify (sensitivity of 0.2 for singular A3 pulley, 0.5 for A2/A4 pulley and 0.33 for A3/A4 pulley ruptures). Receiver operating characteristic analysis was used to evaluate the optimal tendon-bone distance for pulley rupture diagnosis, a threshold which was determined to be 1.9 mm for A2 pulley ruptures and 1.85 for A4 pulley ruptures. This study was the first to carry out a cadaver ultrasound examination of a wide variety of pulley ruptures. Ultrasound is a highly accurate tool for visualizing the A2 and A4 pulleys in a cadaver model. This method of pathology diagnosis was determined to be suitable for injuries to the A2 and A4 pulleys, but inadequate for A3 pulley injuries.

Flexor Tendon Pulley Injuries in Rock Climbers

Closed pulley ruptures are rare in the general population but occur more frequently in rock climbers due to biomechanical demands on the hand. Injuries present with pain and swelling over the affected pulley, and patients may feel or hear a pop at the time of injury. Sequential pulley ruptures are required for clinical bowstringing of the flexor tendons. Ultrasound confirms diagnosis of pulley rupture and evaluates degree of displacement of the flexor tendons. Isolated pulley ruptures frequently are treated conservatively with early functional rehabilitation. Sequential pulley ruptures require surgical reconstruction. Most climbers are able to return to their previous activity level.

Recovery of rock climbing performance after surgical reconstruction of finger pulleys

This study evaluated recovery of sport performance and correction of bowstringing after surgical reconstruction of closed finger pulley rupture in high-level rock climbers. A total of 38 patients treated with an extensor retinaculum graft were assessed. The mean follow-up time was 85 months, and 30 patients returned to their previous climbing level. The mean total active motion score was 96% of the opposite side. All patients had an excellent Buck-Gramcko score. There was no significant difference in grip strength and tip pinch strength in the crimp position between the injured side and the opposite side. A total of 31 patients were examined with ultrasonography. In 18, flexor bowstringing effects had returned to near-normal values. There was an association between rock climbing level recovery and the flexor bowstringing correction (odds ratio, 6.9; 95% confidence interval, 1.1-42.8). If flexor bowstringing was corrected, patients were more likely to regain their preinjury sport performance. The ultrasonography measurement was a useful tool for predicting functional recovery.

LEVEL OF EVIDENCE

4.

Flexor pulley system: anatomy, injury, and management

Flexor pulley injuries are most commonly seen in avid rock climbers; however, reports of pulley ruptures in nonclimbers are increasing. In addition to traumatic disruption, corticosteroid-induced pulley rupture has been reported as a complication of treating stenosing tenosynovitis. Over the last decade, there have been 2 new developments in the way hand surgeons think about the flexor pulley system. First, the thumb pulley system has been shown to have 4 component constituents, in contrast to the classic teaching of 3 pulleys. Second, in cases of zone II flexor tendon injury, the intentional partial A2 and/or A4 pulley excision or venting is emerging as a component for successful treatment. This is challenging the once-held dogma that preserving the integrity of the entire A2 and A4 pulleys is indispensable for normal digit function.

The role of proximal pulleys in preventing tendon bowstringing: pulley rupture and tendon bowstringing

PURPOSE

The aim of this study was to investigate factors that contribute to tendon bowstringing at the proximal phalanx. We hypothesised that: (1) a partial rupture of the A2 pulley leads to significant bowstringing, (2) the location of the A2 rupture, starting proximally or distally, influences bowstringing, (3) an additional A3 pulley rupture causes a significant increase in bowstringing following a complete A2 pulley rupture and (4) the skin and tendon sheath may prevent bowstringing in A2 and A3 pulley ruptures.

METHODS

Index, middle and ring fingers of eight freshly frozen cadaver arms were used. A loading device pulled with 100 N force was attached to the flexor digitorum profundus (FDP). The flexor digitorum superficialis (FDS) was preloaded with 5 N. Bowstringing was measured and quantified by the size of the area between the FDP tendon and the proximal phalanx over a distance of 5 mm with ultrasonography (US).

RESULTS

US images showed that already a 30% excision of the A2 pulley resulted in significant bowstringing. In addition, a partial distal incision of the A2 pulley showed significantly more bowstringing compared to a partial proximal incision. Additional A3 pulley incision and excision of the proximal tendon sheath did not increase bowstringing. Subsequently, removing the skin did increase the bowstringing significantly.

CONCLUSION

A partial A2 pulley rupture causes a significant bowstringing. A partial rupture of the A2 pulley at the distal rim of the A2 pulley resulted in more bowstringing than a partial rupture at the proximal rim.

Feet injuries in rock climbers

While injuries of the upper extremity are widely discussed in rock climbers, reports about the lower extremity are rare. Nevertheless almost 50 percent of acute injuries involve the leg and feet. Acute injuries are either caused by ground falls or rock hit trauma during a fall. Most frequently strains, contusions and fractures of the calcaneus and talus. More rare injuries, as e.g., osteochondral lesions of the talus demand a highly specialized care and case presentations with combined iliac crest graft and matrix associated autologous chondrocyte transplantation are given in this review. The chronic use of tight climbing shoes leads to overstrain injuries also. As the tight fit of the shoes changes the biomechanics of the foot an increased stress load is applied to the fore-foot. Thus chronic conditions as subungual hematoma, callosity and pain resolve. Also a high incidence of hallux valgus and hallux rigidus is described.

Flexor pulley reconstruction

Flexor pulley reconstruction is a challenging surgery. Injuries often occur after traumatic lacerations or forceful extension applied to an acutely flexed finger. Surgical treatment is reserved for patients with multiple closed pulley ruptures, persistent pain, or dysfunction after attempted nonoperative management of a single pulley rupture, or during concurrent or staged flexor tendon repair or reconstruction. If the pulley cannot be repaired primarily, pulley reconstruction can be performed using graft woven into remnant pulley rim or looping graft around the phalanx. Regardless of the reconstructive technique, the surgeon should emulate the length, tension, and glide of the native pulley.

Tendon injuries of the hand

Tendon injuries are the second most common injuries of the hand and therefore an important topic in trauma and orthopedic patients. Most injuries are open injuries to the flexor or extensor tendons, but less frequent injuries, e.g., damage to the functional system tendon sheath and pulley or dull avulsions, also need to be considered. After clinical examination, ultrasound and magnetic resonance imaging have proved to be important diagnostic tools. Tendon injuries mostly require surgical repair, dull avulsions of the distal phalanges extensor tendon can receive conservative therapy. Injuries of the flexor tendon sheath or single pulley injuries are treated conservatively and multiple pulley injuries receive surgical repair. In the postoperative course of flexor tendon injuries, the principle of early passive movement is important to trigger an “intrinsic” tendon healing to guarantee a good outcome. Many substances were evaluated to see if they improved tendon healing; however, little evidence was found. Nevertheless, hyaluronic acid may improve intrinsic tendon healing.

Surgical repair of multiple pulley injuries--evaluation of a new combined pulley repair

PURPOSE

We report on a combined repair of multiple annular pulley tears using 1 continuous palmaris longus tendon graft to restore strength and function.

METHODS

We treated 6 rock climbers with grade 4 pulley injuries (multiple pulley injuries) using the combined repair technique and re-evaluated them after a mean of 28 months.

RESULTS

All patients had excellent Buck-Gramcko scores; the functional outcome was good in 4, satisfactory in 1, and fair in 1. The sport-specific outcome was excellent in 5 and satisfactory in 1. Proximal interphalangeal joint flexion deficit slightly increased in 1 patient and remained the same in the other 5. Climbing level after the injury was the same as before in 4 and decreased slightly in 2 climbers.

CONCLUSIONS

The technique is effective with good results and has since become our standard treatment. Nevertheless, it is limited in patients with flexion contracture of the proximal interphalangeal joint.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

Flap irritation phenomenon (FLIP): etiology of chronic tenosynovitis after finger pulley rupture

After a pulley rupture, most climbers regain the full function of their previously uninjured fingers. However, in some cases of pulley rupture, a persistent inflammation of the tendon sheath is observed. In this study, 16 cadaver fingers were loaded until pulley rupture and then studied for the rupturing mechanism. In addition, two patients with this pathology were investigated using ultrasound and MRI, and received surgery. In 13 fingers, a rupture of one or several pulleys occurred and almost always at the medial or lateral insertion. In one finger, a capsizing of the pulley underneath the intact tendon sheath was observed, leading to an avulsion between tendon and tendon sheath. A similar pathology was observed in the ultrasound imaging, in MRI, and during surgery in two patients with prolonged recovery after minor pulley rupture. In cases of prolonged tenosynovitis after minor pulley rupture, a capsizing of the pulley stump is probably the cause for constant friction leading to inflammation. In those cases, a surgical removal of the remaining pulley stump and sometimes a pulley repair may be necessary.