Cryptorchidism is Associated with Lower Extremity Contracture Location and Severity in Patients with Cerebral Palsy: a PHIS Cohort Study
Eric M. Bortnick, MD, Tanya Logvinenko, PhD, HH Scott Wang, MD, David J. Fogelman, MD, Benjamin J. Shore, MD MPH, Caleb P. Nelson, MD MPH, Michael P. Kurtz, MD MPH.
Boston Childrens Hospital, Boston, MA, USA.
BACKGROUND: Cryptorchidism affects 24-50% of boys with Cerebral Palsy (CP) and the cause remains unknown. Proposed etiologies range from hormonal to muscular. We propose cremasteric contracture as one cause, as the cremaster is likely subject to the same processes that drive other skeletal muscular contractures in CP. We hypothesized that among boys with CP, those with more severe lower limb spasticity, as defined by need for intervention, and those with more proximal muscular contractures (i.e. closer to the groin), are more likely to have undergone orchidopexy for cryptorchidism.
METHODS: Using the Pediatric Health Information System (PHIS) database (2016-2020), we examined male patients with CP and stratified these patients into those with and without lower limb spasticity, as defined by relevant ICD 10 and CPT codes, and compared these groups for occurrence of orchidopexy for cryptorchidism. Demographic characteristics were summarized and compared between patients who underwent and those without orchidopexy using Chi-squared and Mann-Whitney U tests for categorical and continuous variables, respectively. Logistic regression was used to investigate association between orchidopexy and types of contractions and interventions.
RESULTS: 44,561 male patients with CP were identified. 1.6% of patients underwent orchidopexy at a median age of 7.7 years (IQR: 4.5-11.3). 16.0% of patients had lower extremity contractures, 1.1% had only upper extremity contractures, 82.8% had no documented extremity contractures. Presence of lower extremity contracture was significantly associated with a higher rate of orchidopexy for cryptorchidism compared to absence of any extremity contracture (OR=1.33 [1.10-1.59], p=0.0026); importantly, upper extremity contracture was not associated with orchidopexy risk (OR=0.507 [0.16-1.19], p=0.1774). Of the 7,134 patients with lower extremity contractures, need for intervention for extremity spasticity was significantly associated with higher rate of orchidopexy (injection procedures: (OR=2.47 [1.17-6.39], p=0.0337); limb surgical procedure: (OR=2.60 [1.22-6.76], p=0.0259)). Among patients with lower extremity contractures, proximity of contracture to the groin was significantly associated with an increased risk of orchidopexy (proximal contracture vs distal contracture OR=2.52 [1.42-4.96], p=0.0034).
CONCLUSIONS: In the largest series to date on CP and UDT, we show a relationship between lower extremity contracture and orchidopexy in the CP population, as well as association between the location and severity of contracture and the probability of orchidopexy. These findings support a hypothesis that cremaster muscle contracture is an important factor in presence of UDT in CP. Providers should continue to examine for cryptorchidism in boys with CP as they age, particularly those with more severe lower extremity contractures. Future studies may provide insight into whether including treatment of the cremaster in concert with treatment of lower extremity muscle spasticity could prevent future testicular ascent.
Table 1: Demographics
| n | No UDT | UDT | p-value | |
| Overall (%) | 44561 | 43844 (98.39) | 717 (1.61) | |
| Age (median years [IQR]) | ||||
| At last follow up | 10.91 [6.07, 16.05] | 10.95 [6.08, 16.11] | 8.87 [5.69, 12.34] | <0.001 |
| At time of orchidopexy | 7.7 [4.5-11.3] | |||
| Ethnicity (%) | 0.046 | |||
| Hispanic or Latino | 8612 (19.3) | 8448 (19.3) | 164 (22.9) | |
| Not Hispanic or Latino | 32934 (73.9) | 32424 (74.0) | 510 (71.1) | |
| NA | 3015 (6.8) | 2972 (6.8) | 43 (6.0) | |
| Race | 0.053 | |||
| White (%) | 27441 (61.6) | 26974 (61.5) | 467 (65.1) | |
| Non-White (%) | 17210 (38.4) | 16870 (38.5) | 250 (34.9) | |
| Census Region (%) | 0.047 | |||
| Midwest | 11572 (26.0) | 11361 (25.9) | 211 (29.4) | |
| Northeast | 5300 (11.9) | 5234 (11.9) | 66 (9.2) | |
| South | 17864 (40.1) | 17583 (40.1) | 281 (39.2) | |
| West | 9825 (22.0) | 9666 (22.0) | 159 (22.2) | |
| Insurance (%) | 0.194 | |||
| Private | 15553 (34.9) | 15320 (34.9) | 233 (32.5) | |
| Public | 27217 (61.1) | 26761 (61.0) | 456 (63.6) | |
| Other | 1221 (2.7) | 1206 (2.8) | 15 (2.1) | |
| NA | 570 (1.3) | 557 (1.3) | 13 (1.8) | |
| Prematurity (%) | 0.001 | |||
| Yes | 2013 (4.5) | 1961 (4.5) | 52 (7.3) | |
| No | 42548 (95.5) | 41883 (95.5) | 665 (92.7) | |
| Extremity Contracture Location (%) | 0.003 | |||
| Lower | 7134 (16.0) | 6989 (15.9) | 145 (20.2) | |
| Upper Only | 509 (1.1) | 505 (1.2) | 4 (0.6) | |
| None | 36918 (82.8) | 36350 (82.9) | 568 (79.2) |
Table 2: Logistic Regression for Risk of Orchidopexy for UDT
| Whole Cohort (n=44561) | OR | 95% CI | p-value |
| Types of Contractures | 0.0035 | ||
| Upper Only Contraction vs None | 0.51 | (0.16, 1.19) | 0.1774 |
| Lower Contraction vs None | 1.33 | (1.10, 1.59) | 0.0026 |
| Lower Contraction vs Upper Only | 2.62 | (1.10, 8.54) | 0.0585 |
| Lower Extremity Contracture (n=7134) | |||
| Need for Intervention | 0.0361 | ||
| Injection Procedure vs None | 2.47 | (1.17, 6.39) | 0.0337 |
| Limb Surgery vs None | 2.60 | (1.22, 6.76) | 0.0259 |
| Limb Surgery vs Injection Procedure | 1.05 | (0.75, 1.47) | 0.7660 |
| Contracture Location | |||
| Proximal Contracture vs Distal Contracture | 2.52 | (1.42, 4.96) | 0.0034 |
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