Page 11 - The Outcome Question Continued

Novikov et al7 (Kurgan, Russia) studied 131 patients undergoing cosmetic limb lengthening with the Ilizarov apparatus. They achieved a mean of 6.9 cm (range, 2 to 13 cm) of height gain with 5.75 years (range, 1 to 14 y) follow-up. All their patients were tibial monofocal or bifocal lengthening and 6 patients had additional femoral lengthening. The mean duration of the external fixator was 215 days (range, 71 to 390 d). Overall 48 patients (37%) experienced 59 complications during the treatment. These included significant infection in 8 patients (6.1%), equinus deformity in 12 patients (9.2%), and knee flexion deformity in 14 patients (10.7%). Four patients had significant regenerate deformity and 4 more had collapse after frame removal. Furthermore, 6 patients had peroneal nerve neuropathy, 6 more had delayed union, 1 had knee subluxation, 1 patient had a fracture, 1 patient needed reosteotomy for fibula consolidation and another for the tibia. Patient outcome was excellent in 72 (55%), good in 52 (39.7%), satisfactory in 6 (4.6%), and poor in 1 (0.8%). In summary, this study also demonstrated a considerable complication rate with reoperation rate of 16.8%.

Kim et al54 did a systematic review of 547 patients (1581 segments) for stature lengthening and identified phenotypically normal individuals as having higher complications and achieving less length that certain skeletal dysplasias (achondroplasia/ hypochondroplasia).55 It is thought that certain skeletal dysplasias tolerate lengthening well because of inherent soft tissue laxity and high muscle length to bone ratio.1 It is an important consideration when comparing groups of stature patients, as each population will not behave the same. This review compiled 103 etiologically normal patients undergoing stature lengthening with external frames. The mean height gain was 6cm (range, 3 to 8 cm) and rate of healing was reported per centimeter as 32 d/cm (range, 30 to 67 d/cm). The rates of pooled complications reported per segment were 1.06, which was higher than that found in other groups 0.68 (achondroplasia), 0.71 (Turner syndrome) and these differences were statistically significant (P< 0.001). Hence these patients may be, in fact, more difficult to treat, which must be considered when looking at outcomes and comparing them between other studies with different or heterogeneous patient cohorts.

With a new implantable device that has reliable control, we have reduced the incidence of traditional complications associated with stature lengthening. SSL in our series yielded excellent results and low complications compared with the above studies. In light of the reported findings of Kim et al54 regarding stature lengthening etiology, our series is homogenous for short stature nondysplastic patients they concluded are more difficult to treat than other short stature etiologies. Despite this higher risk group, our rate of complications were lower than those reported by any other published series for SSL, as well as the senior author’s (D.P.) previous experience with the ISKD,39,40 especially in comparison to the P2 group. The P2 group had only 1 major complication (bilateral peroneal nerve stretch injury). The improvements in the P2 appear to have corrected the previous issues with the distraction mechanism and nail breakage. Please note that we are not downplaying the 2 cases of fat embolism but recognize that this can occur with any method that uses intramedullary reaming and nailing. Of note, both resolved quickly with supportive measures (oxygen and intravenous fluids).

It is important to emphasize problems that we did not experience and some technical tips that helped avoid complications in our 51 SSL patients treated by the PRECICE. These technical tips are essential to the success of this procedure.
(1) All of the patients achieved union. Reaming after first predrilling the osteotomy site ensures better bone formation due to extrusion of the reamings around the osteotomy site. As noted, it also decompresses the canal to help prevent fat embolism. This should be a routine for femoral lengthening, but avoided with tibial lengthenings due to the risk of compartment syndrome.
(2) There were no compartment syndromes from tibial lengthening. Only the anterior and medial cortices of the tibia were drilled to avoid extrusion of reamings into the deep posterior and anterior compartments, which can lead to compartment syndrome. We recently treated 1 such case from another center. The patient had a permanent foot drop and needed a tibialis posterior tendon transfer.