Page 6 - DISCUSSION

SSL is a controversial indication for limb lengthening. Limb lengthening for stature has been used successfully by numerous authors for the treatment of achondroplasia and hypochondroplasia.1–5 Extensive limb lengthening (ELL) for dwarfism, is controversial but for different reasons. Patients with achondroplasia present with extreme short stature with associated lower limb deformities, short limb to trunk disproportion and rhizomelic disproportion of both upper and lower limbs. Their adult heights are usually between 3 ft 10 inches and 4 ft 4 inches. The goal of ELL for these patients is to increase their heights to over 5 ft tall and ideally to the low normal range for their sex. ELL has been shown to greatly improve function and quality of life.1–5

ELL for dwarfism cannot be compared with SSL of individuals starting at an adult height >5 ft and usually >5th percentile for their sex. Even the technical and strategic aspects of ELL for achondroplasia is not comparable because they are mostly done in childhood before skeletal maturity, whereas SSL is carried out after skeletal maturity. ELL is done repeatedly 3 or 4 times to achieve goals of 30 to 40 cm (12 to 16 inches), whereas SSL goals are usually 5 to 15 cm (2 to 6 inches). SSL goals can usually be achieved by a single bilateral femoral or tibial lengthening or at most, by bilateral femoral and bilateral tibial lengthening. ELL is done for functional reasons, whereas SSL is done for aesthetic and psychological reasons. ELL restores proportions to normal, whereas SSL usually takes normal proportions and alters them.

The senior author (D.P.) has been performing SSL since 1987. During this time, SSL was carried out by several methods: EFOL, LON, and ILN. Between 1988 and 2008, all SSL candidates were required to undergo a psychological evaluation by a single psychologist who is also one of the coauthors (W.W.). At the time, the authors sought to answer 3 questions relating to21 (1) Motivation: What motivates a person to seek SSL?; (2) Selection: Which patients are the best candidates to undergo SSL?; and (3) Outcome: Are patients who undergo SSL satisfied with the outcome?

Thirty patients (21 men, 9 women) were prospectively evaluated by D.P. and W.W. in an IRB-approved study before consideration for SSL using the intramedullary skeletal kinetic distractor (ISKD) ILN between 2000 and 2003.21 The average age was 29 years (range, 16 to 45 y). The average height was 162.3 cm (63.9 inches) for males and 152.9 cm (60.2 inches) for females. The average number of years of education of this group was 16 years and ranged between 10 and 22 years. On the basis of findings from this psychological evaluation, 17 of the 30 (57%) candidates were deemed to be psychologically fit to proceed for surgery. Of the approved 17, only 12 chose to proceed with surgery during the study period. Nine of these participated in a follow-up evaluation after lengthening. The data from this study was used to help answer questions about the motivation, selection, and outcome of SSL. Although this is a small cohort, it provides valuable insight regarding the psychology of patients who seek SSL.

The Motivation Question

Patients who presented for SSL seldom had a history of clear-cut systemic/endocrine disorder or psychosocial etiology, such as failure to thrive. In general, their short stature appeared to reflect genetic and constitutional endowments. In accepted patients, there was no patent psychiatric or psychological disorder; some surgical candidates had body dysmorphic disorder, which was considered a contraindication for SSL, but most accepted patients qualified at most for having an adjustment disorder. In general, patients were more likely to be professional or white collar workers and to have financial means (this is not surprising given the expense of this procedure, which is not covered by insurance).

The literature on stature-related adjustment problems in childhood is mixed. For instance, Steinhausen et al22 concluded short stature can have a negative impact on behavioral adaptation, but Zimet et al23 did not find such a relationship. These different conclusions may be attributed to sample differences.24 Some researchers postulate that the interactions between parenting response, psychosocial stressors, and person variables explain the impact of short stature on self-concept and esteem. Such variables include prolonged caregiving responses,25 juvenilization, 26 stigmatization,27 and self-consciousness.28