Limb lengthening in short stature patients

A series of 140 patients with short stature operated on for limb lengthening (80 had achondroplasia, 20 had hypochondroplasia, 20 had Turner syndrome, 10 had idiopathic short stature due to an undemonstrated cause, 5 regarded their stature as too short, and 5 had a psychopathic personality due to dysmorphophobia that had developed because of their short stature) was reviewed. All patients underwent symmetric lengthening of both femora and tibiae; 10 of these achondroplastic patients underwent lengthening of the humeri. We carried out the 580 lengthening procedures by means of three different surgical techniques: 440 callotasis, 120 chondrodiatasis and 20 mid-shaft osteotomy. In the 130 patients with a disproportionate short stature, the average gain in length was 18.2 +/- 3.93 cm: 43.8% had complications and 3.8% had sequelae; the average treatment time was 31 months. In the 10 patients with proportionate short stature, the average gain in length was 10.8 +/- 1.00 cm: 4 experienced complications and none had sequelae; the average treatment time was 21 months. Patients who underwent lengthening of the upper limbs experienced an average gain in length of 10.2 +/- 1.25 cm: the average treatment time was 9 months and none of them experienced any complications or sequelae. The authors discuss how difficult it is to achieve the benefits of this surgery: they underline the strong commitment on the part of the patients and their families, the time in the hospital, the number of operations and, above all, the severity of those permanent sequelae that occurred.

Complications in limb-lengthening procedures: a review of 49 cases

The purpose of this study was to examine the nature and number of complications relative to magnitude of limb lengthening. Results and complications of 50 limb-lengthening procedures were analyzed. There were 49 patients. Mean age was 21 years (range, 7-48 years). Lengthening was performed in 24 femora, 18 tibiae, 4 humerii, 3 radii, and 1 ulna. Average length gained was 5 cm (range, 3-15 cm) at average follow-up of 48 months (range, 12-76 months). Desired length was accomplished in all but 1 patient. The 69 complications varied in severity, but only 5 of these significantly impaired end results. The most serious complications occurred in patients with >30% bone lengthening. Patients with <15% lengthening had a significantly decreased complication rate. The healing index was lower in children. We conclude that incidence and severity of complications after limb-lengthening procedures are significantly influenced by relative lengthening of bone.

[Progressive limb lengthening with a centromedullary nail versus an external fixator: experimental study in sheep]

PURPOSE OF THE STUDY

Progressive limb lengthening with an external fixator often leads to pin-related complications. A new technique allowing progressive lengthening with a centromedullary nail without external fixation has been developed. This original double-locked device consists of matching male and female components fitted with a continuous thread. Lengthening is achieved via a one-way ratchet system. Twelve back-and-forth movements produce 1.25 mm lengthening.

MATERIAL AND METHODS

We tested this new device on 20 sheep and compared results with external fixation lengthening in 20 other sheep. The animals were divided into groups for sacrifice on days 5, 10, 20, 45 and 90. Serial x-ray were obtained for all animals. In the 45-day and 90-day groups, histomorphometric (trichrome goldner coloration and polarized light microscopy) and densitometric studies were also performed. Bone mineral density (BMD) was determined and bone trabecular density (BTD) and trabecular bone volume (TBV) were expressed in percent of bone trabecular surface area.

RESULTS

Mean lengthening in the 45-day and 90-day groups was 39 mm for the nail and 20 mm for external fixation (1 mm/day). At 90 days, 3 sheep out of 4 had consolidated radiologically with external fixation and 2 out of 4 with the nail. BMD was slightly better for external fixation (0.811 vs 0.695/cm(2)). This difference could probably be attributed to the greater lengthening obtained with the nail. At 45 days, BMD was the same (0.6 g/cm(2)) for both devices. BTD was nearly two-fold higher for the nail compared with external fixation (59.65% vs 32.61% at 90 days), most probably due to primary bone formation. The histomorphometric study allowed an analysis of the osteoid border. Bone quality obtained in the bone regenerate with the nail was superior to that obtained with external fixation. Primary bone formation resulted from membrane ossification with direct transformation of fibroblasts into osteoblasts.

CONCLUSION

This work demonstrated that progressive lengthening can be achieved with a specifically designed centromedullary nail without iterative opening of the operative site. Tolerance to this type of device and quality of the bone regenerate are altogether satisfactory.

Factors leading to hip subluxation and dislocation in femoral lengthening of unilateral congenital short femur

Congenital short femur is a rare and complex deformity. For it to be treated in the most accurate way, we must know of every possible complication. The purpose of this study was to determine the factors leading to hip subluxation or dislocation in patients with an unilateral congenital short femur who underwent a femoral lengthening procedure. Forty-four patients with congenital unilateral short femora types I, II, and IIIA were seen between 1981 and 1993 at Alfred I. duPont Hospital for Children. Seventeen patients had type I, 9 patients had type II, and 18 patients had type IIIA. Twenty patients underwent simultaneous lengthening of the femur and tibia, and 24 patients had primary lengthening of the femur. Eleven patients had an epiphysiodesis of the contralateral femur for residual leg length discrepancies of <6 cm. We observed that in patients with type IIIA, the acetabular dysplasia is severe, as well as the coxa vara deformity, and is associated with progressive subluxation and dislocation of the hip with lengthening. We believe that the combined abnormality of coxa vara and bow of the femoral shaft contributes to hip subluxation and dislocation in congenital short femur in association with an acetabular dysplasia prior to the lengthening. We recommend correction of the varus bow of the femur and the neck-shaft angle to 120 degrees and the acetabular index to <25 degrees prior to lengthening of type IIIA femora.

Bone debridement and limb lengthening in type III open tibial shaft fractures: no infection or nonunion in 9 patients

We retrospectively reviewed a consecutive series of 9 patients with tibial shaft fractures and extensive soft tissue damage, who had completed treatment by means of bone resection and distraction. 4 patients had type IIIB fractures and 5 type IIIC. The median follow-up time after bone resection was 27 (12-43) months. All patients were treated with debridement of devitalized soft tissue and resection of dead bone at the fracture site. The median bone shortening was 4 (3-9) cm. Equal limb-length was restored by proximal corticotomy and lengthening. A free vascular flap in 5 patients and a local flap in 4 patients corrected the soft tissue loss. All soft tissue transfers were successful, except in 1 case, which healed after a new free flap was made. The median union time of the fracture was 8 (4.5-28) months from the injury and 7 (3-10) months from the time of bone resection. There were no deep infections or nonunions and no secondary amputations. This series shows that bone debridement and limb lengthening, with a multidisciplinary approach, is often successful in salvaging limbs at high risk of amputation.

Leg lengthening for short stature in Turner's syndrome

We describe ten patients with Turner's syndrome (karyotype 45, XO) who had leg lengthening for short stature. A high incidence of postoperative complications was encountered and many patients required intramedullary fixation as a salvage procedure. We discuss the reasons for this and highlight the differences between our findings and those of a similar series recently reported. In view of the considerable difficulties encountered, we do not recommend leg lengthening in Turner's syndrome.

Upper limb lengthening

Congenital deficiencies and developmental deformities of the upper extremity often result in complex deformities that include, to variable degrees, shortening and angulation. Because of the nonweight-bearing status of the upper extremity, these deformities are better tolerated and often of less functional significance than their counterparts in the lower extremity. The need for lengthening therefore is less common in the upper extremity than in the lower extremity. When planning a lengthening procedure to the upper limb, the surgeon must be aware of some specific indications, goals, and complications. In the final analysis, one must weigh the risk of upper limb lengthening against the benefits. In fact, there are many pitfalls, and it is not a surgery to be undertaken lightly. In the hands of experienced specialists, it can achieve excellent results. The potential complication rate is high initially, but tends to diminish with increasing experience. The authors believe that the functional, cosmetic, and psychological benefits of upper limb lengthening outweigh the risk of permanent sequelae and functional impairment in selected patients.

[The mechanism of biological adaptability of peripheral nerves during limb lengthening in rabbits]

OBJECTIVE

To study the mechanism of subclinical damage and repairing process of peripheral nerves during gradual tibial lengthening.

METHODS

Histological investigation, electrophysiological examination of tibial nerve and GAP-43 mRNA expression of sciatic nerve related spinal cord and ganglion were observed in 10%, 20%, 30%, 40% lengthening, and at 2, 4, 8 weeks phases after 40% limb lengthening in 80 rabbits.

RESULTS

With the increase of elongation, severer and more obvious nerve damage and stronger expression of GAP-43 mRNA happened. However, nerve regeneration occurred synchronously and the changes recovered gradually within 8 weeks.

CONCLUSION

Damage of the peripheral nerves is common during limb lengthening. But, it is temporary and recoverable in case the lengthening rate is < 1 mm/d.

[Limb lengthening in dwarfism]

Limb lengthening in dwarfism has become a standardised procedure with a good prognosis. In most cases external fixation is used. Gain of leg length up to 15 cm and more is possible in the lower leg and the femur and 8.5 cm in the humerus. Limb lengthening is useful in many cases of dwarfism due to skeletal dysplasia. There are a number of risks and possible complications involved and the procedure also requires considerable time. We report the results of 48 patients with dwarfism operated on in the Orthopädische Kinderklinik Aschau (Orthopaedic Hospital for Children). It must not be recommended as a normal tool in handling the problems of dwarfism, but it makes sense in some cases of dwarfism. We describe and discuss the prerequisites for the operative treatment.

Experimental study of peripheral nerve injury during gradual limb elongation

The purpose of this study was to clarify how fast the peripheral nerve can be elongated gradually without inducing nerve conduction block, and to assess whether the damage to the peripheral nerve is reversible. Rabbit femur was gradually elongated to 30 mm at the rate of 0.8 mm/day, 2.0 mm/day, and 4.0 mm/day to stretch the sciatic nerve. Immediately after and eight weeks after elongation, each group was estimated. Elongation of the Ranvier's node, which was likely the cause of conduction block, was observed and its severity increased with elongation speed. There was no Wallerian degeneration even when conduction block was complete. There was little damage to the sciatic nerve in the group of 0.8 mm/day. Damage in the group of 2.0 mm/day immediately after elongation had a tendency to recover by eight weeks, but there was no such tendency in the group of 4.0 mm/day.

Attempted limb lengthenings beyond twenty percent of the initial bone length: results and complications

In response to historic guidelines suggesting limits to the amount of limb lengthening, we report the results and complications of those patients in whom the initial goal of lengthening exceeded 20% of the initial segment length. Thirty-one patients underwent a total of 35 attempted lengthenings with a mean follow-up of 38.6 months. Limb-length discrepancy was the primary indication in all but one case. With an average goal of 35% of the original bone length, we achieved a mean gain of 33%. Lengthening to within 2.5 cm was achieved in 31 (89%) of 35 cases, and significantly more successful with goals extending < or =55% of the initial bone length (p<0.05). Treatment times extended a mean of 8.7 months with a healing index of 37 days/cm. By Paley's classification scheme, all had problems, in addition to an average of 1.3 obstacles and 0.9 complications per segment lengthened. In 23 patients with extended follow-up, good to excellent results were achieved in 78%, and were significantly more successful with goals < or =55% (< or =0.05).

One-stage lengthening and derotational osteotomy of the femur stabilised with a gamma nail

OBJECTIVES

To study the results of a one-stage lengthening and derotational osteotomy stabilised with a Gamma nail.

DESIGN

Retrospective study.

SETTING

2 hospitals, The Netherlands.

PATIENTS

5 patients after failed osteosynthesis of femoral fractures.

INTERVENTIONS

Mean lengthening of 3 cm and derotation of 30 degrees.

MAIN OUTCOME MEASURES

Complications and functional results, after a mean follow-up of 43 months (range 30-57).

RESULTS

Two patients required dynamisation and a cancellous bone graft to achieve union, which resulted in 1 and 1.5 cm loss of length. One patient had a temporary peroneal neurapraxy. No infections were observed.

CONCLUSIONS

Our method is not an ultimate solution, but is suitable for one-stage lengthening and derotation osteotomies.

Medial arch strain after lateral column lengthening: an in vitro study

Posterior tibial tendon dysfunction with concomitant progressive flatfoot deformity is associated with ligamentous failure along the medial arch. Lateral column lengthening is being used alone and in combination with other procedures with the expectation that it contributes to restoring and maintaining the arch. The primary objective of this study was to examine the effect of lateral column lengthening on medial arch strain. A secondary objective was to examine the effect of subtalar, talonavicular, double and triple fusions on medial arch strain. Whole cadaver feet were subjected to vertical loads while in a plantigrade position. Spring ligament length was monitored using liquid metal displacement gauges. Two outcomes were examined: the length of the ligament and the change in length of the ligament per unit of applied load. Ligament length was unchanged after lateral column lengthening. Ligament length was decreased after talonavicular, double and triple arthrodeses, consistent with the ligament being protected by these fusions. The change in length per unit of applied load after simulated lateral column lengthening was comparable to that for the intact foot, which is consistent with the ligament remaining functional during weightbearing and not being overloaded.

Relationship between radiologic morphology of the bone lengthening formation and its complications

The objective was to study the different types of lengthened bone regeneration and their development during the various phases of the process to correlate them with patient factors and the surgical technique used, and to establish a possible relation between the development of the bone lengthening formation and the problems or complications. The authors studied the radiographs of a random group of 55 patients taken at three points during the course of treatment. The callus was classified with regard to its transverse diameter and the presence or absence of hypodense areas. The overall callus type was significantly influenced by the etiology, the osteotomy site, and the percentage lengthened. The percentage by which the limb was lengthened at the beginning of the process influences the overall morphology of the callus. Poor callus had been lengthened the most, atrophic callus the least. There was a correlation between the morphology of the overall callus at the end of treatment and the percentage lengthened, and between the percentage lengthened and the presence of bands at the end of treatment. The authors also found a significant correlation between age and the appearance of bands at the end of distraction. A central band was found among younger patients. The type of osteotomy affected the overall callus at the end of distraction and at the end of treatment and also influenced the transverse diameter. All the elongations with poor bone formation at the end of treatment were found to have undergone a diaphyseal osteotomy. The most common complication at the first follow-up and at the end of distraction was angulation. The diameter of the callus and the presence of bands at the end of treatment were significantly related to the complications. Fracture occurred in the first 2 weeks after removal of the external fixator in 88% of cases and in the third and fourth week in the rest. However, the segment had no significant influence on the appearance of complications. Lengthened callus with incomplete trabecular formations and hypodense areas at the end of the treatment has a high risk of fracture at the end of treatment. Callus with axial deviation, hypodense areas, or an insufficient transverse diameter during the lengthening procedure must be manipulated so that it reaches the maturing phase in better condition.

Nerve palsy after leg lengthening in total replacement arthroplasty for developmental dysplasia of the hip

We reviewed 508 consecutive total hip replacements in 370 patients with old developmental dysplasia of the hip, to relate the amount of leg lengthening to the incidence of nerve palsies after operation. There were eight nerve palsies (two femoral, six sciatic), two complete and six incomplete. We found no statistical correlation between the amount of lengthening and the incidence of nerve damage (p = 0.47), but in seven of the eight hips, the surgeon had rated the intervention as difficult because of previous surgery, severe deformity, a defect of the acetabular roof, or considerable flexion deformity. The correlation between difficulty and nerve palsy was significant (p = 0.041). We conclude that nerve injury is most commonly caused by direct or indirect mechanical trauma and not by limb lengthening on its own.

Periosteum and bone marrow in bone lengthening: a DEXA quantitative evaluation in rabbits

We quantitatively studied the role of periosteum and bone marrow-endosteum during lengthening in 18 growing rabbits, comparing four surgical procedures: 1) periosteum and bone marrow preservation, 2) periosteum preservation, bone marrow destruction, 3) periosteum destruction, bone marrow preservation, 4) periosteum and bone marrow destruction. An external fixator was set on one femur, the other serving as a control. Distraction began on day 5 and stopped on day 25 (0.25 mm/12 hours). On day 30, femora were harvested with a layer of muscle. Area, bone mineral content and density were measured by dual-energy x-ray absorptiometry. Procedure 2 showed the highest increase in bone mineral content around the elongated callus (127%) compared to procedures: 1 (81%), 3 (25%) and 4 (-8%, i.e., resorption of bone ends). A statistically significant effect on bone formation was observed when preserving (vs. destroying): 1) periosteum, 2) bone marrow (effect observed only around the distraction gap), 3) periosteum and bone marrow in combination. Periosteum alone forms a larger callus, with more mineral content than bone marrow alone, and destruction of both results in the absence of bone formation around the distraction area. Careful preservation of periosteum is essential to bone healing. Formation of bone with a large mineral content does not require bone marrow preservation, but there is an interaction effect on healing between bone marrow and periosteum.

Pseudoaneurysm after high tibial osteotomy and limb lengthening

A case of a young man with anterior tibial artery rupture and pseudoaneurysm formation that occurred during lengthening of a scarred limb is presented. Leg length discrepancy occurred because of previous distal femoral and proximal tibial fractures. Two corrective operations were performed 11 and 2 years earlier at another hospital. As limb deformity persisted, distal femoral and proximal tibial osteotomies combined with limb lengthening were performed. The aim was to achieve 120 mm (70 mm femoral, 50 mm tibial) lengthening. The operative and early postoperative course was uneventful. Twenty-six days after surgery (when femoral and tibial lengthening was 13.5 mm and 5.5 mm, respectively), blood began oozing from the operative scar during limb distraction. At 70 days after surgery (when femoral and tibia lengthening was 41.5 mm and 14 mm, respectively), a rupture and pseudoaneurysm of the anterior tibial artery became apparent. Documentation of a normal pulses in the foot after surgery, the late presentation of pseudoaneurysm, and the initiation of bleeding by limb distraction indicate that limb lengthening either aggravated an unrecognized arterial injury or precipitated de novo rupture of the anterior tibial artery scarred from previous trauma. The pseudoaneurysm was treated successfully by transarterial embolization.

The diameter of callus in leg lengthening: 28 tibial lengthenings in 14 patients with achondroplasia

We investigated the relation between callus diameter during bone distraction and the occurrence of late fracture and deformity. We retrospectively reviewed 28 tibial lengthenings in 14 patients with achondroplasia. The minimal diameter of the lengthened zone was measured on radiographs, when the sliding mechanism of the lengthening device was released, and the callus diameter ratio in two planes (CDR; diameter of the callus/diameter of the tibia at the level of the osteotomy end) was calculated. The CDR correlated negatively with the distracted length. Late fracture or late angular deformity occurred in 6 of the 28 lengthenings. When the CDR was 85% or more in both planes, these complications did not occur, but when the CDR was 80% or less in either plane, they occurred in 6 of 20 bones. Careful attention should therefore be given not only to the continuity of the callus but also to its diameter.

[Analysis of complications during lower extremity lengthening]

Lengthening is generally accepted method of treatment for extremity length discrepancy. This attractive method carries the risk of many complications that may ruin primary treatment plan. The aim of this paper was to analyze complications and their management in own material consisting of 60 extremities in 58 patients aged 8-37 years. Limb length discrepancy was caused by congenital bony hypoplasia in 44 cases, trauma in 8 and infection in 8 cases. Initial shortening ranged from 4 to 15 cm (mean 6.5 cm). Ilizarov technique was used in 20 cases, Wagner method in 6 cases and DeBastiani in 34 cases. Expected elongation has been achieved in 60% cases; in remaining 40% complications occurred. New bone formation disturbances and axial malalignement were among most severe ones. An autogenic marrow injections were used to stimulate callus formation, osteogenon was administered. Axial malalignement was corrected by osteotomy. Percentage of complications decreased as number of elongations performed increased.

[The effect of non-parallel distractor fixation to bone on deformities of the limb axis in bone lengthening of the limb]

The paper presents causes of limb axis deflecting during bone lengthening. It has been proved mathematically, that axis deflection is caused by incorrect setting up the distractor (i.e. not parallel to the bone axis) irrespective of the structure of apparatus used.

Influence of femoral lengthening on hip joint space in posttraumatic femoral shortening

We performed femoral lengthening for post-traumatic femoral shortening in 14 patients (10 men). The mean age was 26 (17-33) years. The callotasis method was employed using an Orthofix or Hifixator monolateral external fixator. The average length gained was 6 (3-13) cm, equal to 16 (7-36)%. The mean narrowing ratio of the hip joint space during lengthening was 9 (0-26)% and the narrowing persisted at the final follow-up. Cases with narrowing greater than 5% had a longer time between the development of the shortening and the lengthening than the others (p = 0.03). Our findings indicate that femoral lengthening for posttraumatic femoral shortening should be done as early as possible to prevent the development of joint space narrowing during the lengthening procedure.