Total Coccygectomy for Refractory Coccydynia: A 10-Year Single-Center Retrospective Cohort Study with Comprehensive Outcome Analysis

Technical Summary: Total Coccygectomy for Refractory Coccydynia

Problem Statement
Coccydynia, or localized pain of the coccyx, affects approximately 1–5% of patients presenting with low back pain. While the majority of cases respond to conservative management (NSAIDs, cushions, injections, physical therapy), a subset of 10–30% develops chronic, refractory symptoms. For these patients, total coccygectomy is considered the definitive surgical intervention. However, existing literature on surgical outcomes is often limited by small sample sizes, heterogeneous patient selection, short follow-up periods, and a lack of data from low- and middle-income countries (LMICs). This study addresses the need for outcome data on standardized total coccygectomy within a tertiary neurosurgical center in Pakistan.

Methodology
This was a single-center, retrospective observational cohort study conducted at Combined Military Hospital, Rawalpindi, covering a 10-year period from May 2009 to May 2019. The study adhered to STROBE guidelines.

• Cohort: From an initial pool of 27 patients, 21 met the inclusion criteria: age ≥14, chronic coccydynia persisting ≥6 months despite optimized conservative therapy, localized tenderness, radiographic evidence of pathology (hypermobility, subluxation, spicule, or degeneration), and a minimum postoperative follow-up of 24 months.
• Exclusions: Patients were excluded for underlying malignancy, active infection, congenital anomalies, prior coccygeal surgery, incomplete records, or loss to follow-up before 24 months.
• Surgical Technique: All patients underwent total coccygectomy under general anesthesia in the prone position using a 4-cm midline incision. The study utilized a standardized proximal-to-distal (Key) technique: the sacrococcygeal joint was identified and disarticulated first, followed by subperiosteal dissection of the coccygeal segments. This approach aimed to identify the plane between the coccyx and rectum early to minimize visceral injury. The distal tip was removed last, and the lower sacrum was beveled for smooth contouring before layered closure.
• Outcome Measures: The primary outcome was the change in pain severity measured by the Visual Analogue Scale (VAS, 0–10) from preoperative assessment to final follow-up. Outcomes were categorized as:
  • Excellent/Good: ≥50% VAS reduction or final VAS ≤3.
  • Fair: VAS 4–5.9.
  • Poor: VAS ≥6.
  • Complications were recorded as major or minor.
• Statistical Analysis: Pre- and postoperative VAS scores were compared using a paired two-tailed t-test (significance set at P < 0.05) using IBM SPSS Statistics.

Key Results

• Demographics: The cohort consisted of 21 patients (9 males, 12 females) with a mean age of 34.2 years. The mean duration of preoperative symptoms was 17.2 months. Etiology was traumatic in 42.9% and idiopathic/degenerative in 57.1%.
• Pain Reduction: There was a statistically significant reduction in pain. The mean preoperative VAS score of 8.4 ± 1.1 decreased to 3.2 ± 1.9 postoperatively (mean reduction of 5.2 points; P < 0.001).
• Functional Outcomes:
  • Excellent/Good: 15 patients (71.4%) achieved this outcome (VAS <3).
  • Fair: 3 patients (14.3%) showed reduced pain (VAS 3–6).
  • Poor: 3 patients (14.3%) had persistent severe pain (VAS >7).
• Complications: The overall complication rate was 19.0% (4/21), consisting entirely of wound infections.
  • Major: 1 patient (4.8%) required vacuum-assisted closure (VAC) for a major wound infection.
  • Minor: 3 patients (14.3%) had minor infections managed conservatively with daily dressings.
  • Adverse Events: There were no instances of rectal injury, neurological deficits, or reoperations.

Significance and Claims
The paper claims that total coccygectomy is a safe and effective "last-resort" option for selected patients with refractory coccydynia, particularly in settings where access to chronic pain management services may be limited.

• Clinical Efficacy: The study demonstrates that a standardized surgical approach yields significant pain relief, with over 70% of patients achieving excellent or good outcomes. This aligns with international literature while providing data from an underrepresented LMIC population.
• Safety Profile: The use of the proximal-to-distal subperiosteal technique resulted in no rectal injuries or neurological deficits, supporting the safety of this specific surgical approach.
• Contextual Relevance: The authors highlight that the findings are particularly relevant for low- and middle-income countries, where patients often present with advanced, refractory symptoms due to limited access to earlier interventions.
• Limitations: The authors modestly acknowledge limitations, including the retrospective design, small sample size (n=21), lack of a control group, and a mean follow-up of only six months (despite the 24-month inclusion criteria, the text notes a mean of six months, which may reflect the specific timing of the final data point or a discrepancy in the text; however, the authors explicitly state the mean follow-up restricts long-term durability assessment). They also note the absence of validated functional outcome measures (e.g., Oswestry Disability Index) and the inability to perform robust subgroup analyses due to sample size.

Conclusion
The study concludes that total coccygectomy provides significant pain reduction with acceptable complication rates for refractory coccydynia. While the results support the procedure as a definitive treatment, the authors emphasize the need for larger, prospective, multicenter studies with longer follow-up and standardized functional outcome measures to confirm long-term durability and generalizability.