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Summary: Stature lengthening for short stature, often referred to as cosmetic stature lengthening, is controversial. Previous methods and devices have been fraught with high complications rates. The PRECICE intramedullary lengthening nail offers a superior alternative for these patients due to its minimal incision technique, remote controlled gradual distraction, the rate of which can be accurately modulated and the direction reversed, if necessary. The purpose of this study is to report the results of the PRECICE for short stature lengthening and to compare them to previously reported results with other methods. Another objective of this paper is to discuss the indications for treatment by exploring the motivation, selection, and outcome of such treatment. Fifty-one patients were lengthened for short stature with the PRECICE; 25 with the PRECICE 1 (P1) and 26 with the PRECICE 2 (P2). There were 7 bilateral tibial and 22 bilateral femoral lengthenings in the P1 and 4 bilateral tibial and 25 bilateral femoral lengthenings in the P2 groups. In total there were 58 P1 and 58 P2 bone segments lengthened. Lengthening was up to 6.5cm for P1 and 8 cm for P2 with an average increase of 5.2 cm for P1 and 6.0cm for P2. There were 7/58 (12.1%) implant failures for P1 and 1/58 (1.7%) for P2. The P1 failures were due to breakage of the nail through a weld in the nail in 4 cases and the breakage of the mechanism in 3 cases. The P2 failure may be related to too little overlap of the wider nail tube into the distal bone segment combined with potential stress fracture propagation due to small slots at the end of the larger tube of the nail. All nail breakages occurred in patients who did not comply with the weight-bearing restrictions. The new clutched mechanism and 1-piece outer tube construction in the P2, prevented fracture through the nail and mechanism failure in the P2 compared with the P1. Stress propagation by the small slots at the end of the P2 led to redesign with elimination of slots and release of the P2.1. There were 2 cases of suspected fat embolism despite venting and 1 deep vein thrombosis upon stopping anticoagulation, from which the patient recovered without further complication. There was 1 femur fracture through an anteroposterior femoral locking screw and 1 bilateral peroneal nerve stretch injury that fully recovered. All patients consolidated the distraction gap of the femurs and/or tibias without additional surgery. All returned to previous activities including sports. In comparison to previously published methods, the P2 had the lowest complication rate with the best overall reported results.

Key Words: stature lengthening—cosmetic lengthening—limb lengthening— stature dysphoria—PRECICE—implantable limb lengthening.
(Tech Orthop 2014;29: 72–85)

Limb lengthening has traditionally been used for treatment of limb length discrepancy. Such lengthening surgery is unilateral. Bilateral limb lengthening is used to increase stature and is referred to as stature lengthening. Stature lengthening is indicated for patients with dysplasias1–5 (eg, achondroplasia, hypochondroplasia), constitutional short stature (patients under the 5th percentile for height) and for increasing height in normal statured individuals6,7 (patients >5th percentile). This latter application has been referred to as “cosmetic stature lengthening” because of its apparent similarity to cosmetic procedures undertaken to improve appearance and self-esteem. Owing to the intensity of psychological discomfort that prompts short stature patients to seek limb lengthening, as well as the prolonged interruption and loss of independence imposed by postsurgical rehabilitation, the term “cosmetic” insufficiently describes the nature of the intervention. Thus, this application will be referred in this manuscript as short stature lengthening (SSL). SSL is a controversial application of limb lengthening. Although controversial, SSL has been previously reported using various techniques including external fixation only lengthening (EFOL),6,7 lengthening over nail (LON),8,9 lengthening and then nailing (LATN),10 and implantable lengthening nails (ILN).11–16

METHODOLOGY

Data were retrospectively gathered into a database on consecutive patients who underwent SSL using either the PRECICE 1 (P1) or PRECICE 2 (P2) nail (Fig. 1). A total of 51 patients and 116 PRECICE nails (58 nails P1 and 58 P2) were implanted between January 2012 and June 2014. To be included in this study, patients had to complete distraction and consolidation of their bone segments to the point of walking full weight-bearing without walking aids. All patients were carefully evaluated on initial presentation to exclude skeletal dysplasia, endocrinopathy, systemic illness, and any limb insertion, quantitate body proportions (lower limbs to height and tibia to femur), preoperative leg length discrepancy, and alignment. A prerequisite for surgery was skeletal maturity of the lower limbs with closure of the lower limb physes. All patients had to stay in the vicinity until the end of the distraction phase, do daily physiotherapy at our center throughout the distraction phase, comply with weight-bearing restrictions until radiographic bone consolidation (distraction and consolidation phases), and come in for biweekly follow-up radiographs and examination by the surgical team during the distraction phase. The purpose of these visits is to monitor their muscle flexibility, nerve function, joint range of motion, and bone formation, as well as, to monitor that the amount of lengthening expected is confirmed by radiographic measurement. Although the ERC device has a digital read out of length, it only displays the presumed amount of lengthening. If a patient does not push the device down deep enough, they can get behind on the lengthening because the ERC magnet needs to be within 5.5 cm of the nail magnet to rotate it. It is not uncommon for patients to get behind on lengthening one side compared with the other. Typically, they are always on track on the right side if they are right-handed and vice versa. It seems they put less pressure on their thigh with the ERC device on the side opposite their dominant hand. Initially, the FDA required distraction with ERC to be done at the physician’s office. The FDA approved home use of the ERC as of October 2012 (Fig. 2). Before this date, the lengthening was performed daily by our orthopedic technologist. After October 2012, all patients were taught to perform the lengthening at home using the ERC device and the lengthening was performed by the patient or their personal care giver. All patients underwent preoperative physical and psychological evaluation by the surgeon. Psychologically, we evaluated patient motivation and objectives in an effort to evaluate how realistic patients’ goals were, compared with the achievable safe lengthening goal. A detailed mental health history was obtained, and the patient’s mood, thought form, suicidal risk, and reality conformance were assessed by the surgeon. Evaluation by a psychologist or psychiatrist was required when the surgeon believed that the mental health history was concerning or the patient reported major psychiatric disorder, extended previous use of psychiatric drugs, or any history of self-injury, suicidal ideation, or attempt. Only 1 patient in the study group was mandated to have a psychiatric evaluation before the lengthening.