Avulsion Amputation Research Articles

Traction avulsion amputation of the major upper limb: a proposed new classification, guidelines for acute management, and strategies for secondary reconstruction.

Major replantation of a traction avulsion amputation is undertaken with the goal of not only the reestablishment of circulation, but also functional outcome. This type of amputation is characterized by different levels of soft-tissue divisions involving crushing, traction, and avulsion injuries to various structures. Between 1985 and 1998, 27 cases were referred for secondary reconstruction following amputation of the upper extremity involving both arm and forearm. Replantation was performed by at least 12 qualified plastic surgeons using different approaches and management, resulting in different outcomes. Initial replantation management significantly affects the later reconstruction. For comparing studies and prognostic implications, the authors propose a new classification according to the level of injury to muscles and innervated nerves: type I, amputation at or close to the musculotendinous aponeurosis with muscles remaining essentially intact; type II, amputation within the muscle bellies but with the proximal muscles still innervated; type III, amputation involving the motor nerve or neuromuscular junction, thereby causing total loss of muscle function; and type IV, amputation through the joint; i.e., disarticulation of the elbow or shoulder joint. Some patients required further reconstruction for functional restoration after replantation, but some did not. Through this retrospective study based on the proposed classification system, prospective guidelines for the management of different types of traction avulsion amputation are provided, including the value of replantation, length of bone shortening, primary or delayed muscle or nerve repair, necessity of fasciotomy, timing for using free tissue transfer for wound coverage, and the role of functioning free muscle transplantation for late reconstruction. The final functional outcome can also be anticipated prospectively through this classification system.

REPLANTATION OF THE THUMB, ESPECIALLY AVULSION

In replantation for avulsion amputation of the thumb, high survival rate of replanted digits depends on good debridement, good arterial repair with vein grafts or neurovascular bundles, and good coverage, with loose closure of the wound. The functional success depends on liberal use of nerve and tendon grafts or transfer; subsequent procedures, such as tenolysis and opponensplasty; and backup procedures for cases with severe soft tissue avulsion or long ischemic periods. All thumb amputations should be explored in the operating room for evaluation of replantability. If it is still questionable, an experienced microsurgeon should be consulted to choose between replantation and an alternative reconstructive procedure.

FUNCTIONING FREE-MUSCLE TRANSPLANTATION FOR THE UPPER EXTREMITY

Functioning free-muscle transplantation (FFMT) is an advanced microneurovascular technique indicated in patients who have an injury with major functional muscle or muscle group loss or denervation and no locally available or ideal musculotendinous donor units. Over the 9-year period, from 1986 to 1994, 47 FFMTs were applied in patients who had severe hand and upper-extremity injuries (not including brachial plexus injury). Thirteen patients had 15 FFMTs to reconstruct muscle loss caused by severe Volkmann's ischemia. Seventeen patients had 21 FFMTs for reconstruction after severe crushing and traction injuries of the forearm or arm, with major muscle loss or major nerve injury. Nine patients, with 11 FFMTs, sustained major limb avulsion amputation for which replantation without nerve repair was done initially. FFMT was the only technique available to resolve the motor deficit and consequent deformity. Most patients achieved significant functional improvement.

A morphological study of the long-term repair process in experimentally stretched but unruptured arteries and veins

As many avulsion amputations are incomplete and the vessels remain intact, the immediate pathology and long-term repair process (to 3 months post-injury) of experimentally stretched but unruptured rabbit femoral arteries and veins were examined. In stretched arteries, circumferential skip lesions involving endothelium, internal elastic lamina (IEL) and media occurred frequently and often up to 3 cm from the point of stretch. Medial smooth muscle cells (SMC) were significantly damaged or lost at lesions. Macrophages and neutrophils were found in lesions 1–4 days post-injury. Between 2–4 days, lesions were covered by endothelium and synthetic state SMC appeared in the media. At 1 week, a thin neointima (which persisted to 3 months) covered many lesions. The media at lesions gradually filled with SMC but generally remained disorganised even at 3 months post-injury. Stretching caused tears in vein walls, particularly close to the point of injury. There was no evidence of venous damage or repair in specimens examined 3 weeks and 3 months post-injury.

Double Fillet of Foot Free Flaps for Emergency Leg and Hand Coverage with Ultimate Great Toe to Thumb Transfer

A 42-year-old woman presented with avulsion amputation of her right leg 14 cm below the knee joint and a hemihand amputation of the opposite hand. Two free flaps, taken from the amputated foot, were used to cover the injured extremities. The sole fillet flap was used to preserve length and cover the injured leg, while the dorsal fillet flap covered the injured hand and provided ectopic storage for the great toe. The great toe was later transferred on a pedicle for thumb reconstruction. Spare parts surgery is now a well-accepted technique. This case demonstrates maximum utilization of amputated parts for functional and aesthetic reconstruction.

Thumb replantation: Survival factors and re-exploration in 122 cases

We analyzed 122 cases of replantation following complete amputation of the thumb and correlated various factors with rates of survival. The overall survival rate of thumb replantation was 71%. The type of amputation markedly affected survival rate. In minimally damaged amputations, the time period from injury to the start of surgery was the only significant factor related to survival. Other factors such as age, smoking history, amputation level, the number of vessels reconstructed and the method used did not relate statistically to survival. With avulsion amputations, the survival rate of replantation at and proximal to the MP joint was significantly better than replantation distal to the MP joint. 20 thumbs required re-exploration for vascular compromise; nine of these were salvaged (45%).

Avulsion Injuries of the Thumb

Avulsion amputations of the thumb are generally thought to have a worse prognosis after replantation than other amputations. We report the results of 17 thumbs that had an avulsion amputation and were replanted. Fourteen of the 17 survived (82 percent). Our experience indicated that the survival rate was improved by restoring continuity of at least two veins and two arteries, using a Y-shaped vein graft and the princeps pollicis artery for the source of arterial circulation. Nerve grafts were used to bridge defects in avulsed digital nerves. When possible, avulsed tendons were reattached to their muscle. Key pinch strength was 60 percent of normal, and grip strength was always less than that of the normal hand. The age of the patients and the cold ischemia time had no significant effect on either survival or function of the replanted thumb. When excellent venous backflow occurred immediately after the vessel repair and continued for at least 20 minutes, the thumb always survived without complications.

Rotating shaft avulsion amputations of the thumb

In a three-year period twenty-nine patients were treated for rotating shaft avulsion amputations of the thumb. Twenty-three thumbs were considered suitable for replantation. A staged approach, consisting of primary replantation and secondary nerve grafting and tendon reconstruction, was used because of concern that survival rates would be low. Survival was achieved in nineteen of twenty-three replantations. At mean follow-up of 20.5 months grip strength was 94.6% of the unaffected side and key pinch was 77.1%. Five patients achieved a two-point discrimination less than five millimeters. Success was better anticipated and now a full reconstruction is carried out in a single-stage procedure.

Results of flexor tendon tenolysis after replantation in the hand

Thirty-seven replanted digital units and four thumb replantations had a flexor tendon tenolysis at an average of 10 months after replantation. The results were assessed by measuring total active motion, potential active motion, and by the formula of Strickland and associates. The total active motion increased from a mean pretenolysis of 72 degrees to 130 degrees. The potential active motion increased from a mean of 43% to 70% after tenolysis. Both of these improvements were statistically significant ( p < 0.001). The formula of Strickland and associates rated 13 excellent, 11 good, 6 fair, and 11 poor. The thumbs had two fair results and two poor results. Poor results were also seen in crush or avulsion amputations, hands with more than two digits amputated, and those requiring a proximal interphangeal joint capsulotomy. Little difference was found related to the number of arteries or tendons repaired. Complications included tendon rupture and infection. No digits were lost. The results of this study would support flexor tendon tenolysis after replantation of fingers but not replanted thumbs.

Salvage of the ring avulsed finger in heavy manual workers

Complete ring avulsion amputation (class III) injuries are difficult management problems, especially when they occur in heavy manual workers. By excising the bit of bone detached with the skin tube, opening up the skin tube into a flap and replanting it onto the proximal stump, two such cases were salvaged successfully, with early recovery of function. The fingers were shortened by 1.5 cm, had a normal nail, touch sensation and absence of cold intolerance and pain. Both of the patients returned to work in 4 months.

Primary microsurgical repair of ring avulsion amputation injuries

Primary microsurgical repair of ring avulsion amputation injuries

Primary microsurgical repair of ring avulsion amputation injuries

Patients with ring avulsion injuries of the fourth and fifth digits often demand attempts at reconstruction rather than completion of the amputation. In the past, this has led to reconstruction involving a staged series of operations with results that were often less than desirable. Seven patients with ring avulsion amputation injuries that were reconstructed by use of microsurgical reanastomoses are reported. All were classified as either Carroll type IV or Urbaniak type III. Six patients (85%) had a successful replantation leading to a useful finger. The operating time averaged 5.5 hours. On average, 1.9 arteries (range 1 to 2) and 3.3 veins (range 2 to 5) were repaired for each digit. Average hospital stay was 6.7 days (range 4 to 15). Average range of motion was 0(2)/84(2) for metacarpophalangeal joint and 15(2)/90(2) for proximal interphalangeal joint (PIP) with distal interphalangeal joint ankylosis at between 0(2) and 15(2) of flexion. Sensibility was protective in all cases and good in three. If the PIP joint was damaged, completion of amputation was the treatment of choice. If the amputation is distal to the PIP with a functional superficialis tendon, primary microsurgical repair is the treatment of choice in complex ring avulsion injuries.

Interpositional microvascular vein grafting

The application of interpositional microvascular vein grafting in replantation surgery, a detailed account of the technique developed and utilised in the microvascular research and training laboratory, and clinical experience with this technique are described. Vein grafting is of particular value to eliminate tension in anastomoses, bridge vascular defects, and has made feasible the salvage of severe crushing and avulsion amputation in the hand.

THE VASCULAR COMPLICATIONS OF DIGITAL REPLANTATION

A report on a series of 18 digital replantations is presented. The overall survival of digits was 13 (72%). All but one of the crush and avulsion amputations developed vascular complications. Venous insufficiency was much more commonly seen than arterial. Substantial blood loss was the rule in all digits which developed further vascular problems. A conservative approach is advocated for the majority of these complications.