I. Imaging Findings

Based on the right hip joint X-ray and MRI provided by the patient (as well as preoperative and postoperative X-rays), the following main features are noted:

• On the preoperative right hip X-ray, the joint space is markedly narrowed, and there is bony destruction or irregular margins between the femoral head and the acetabular rim, suggesting an infection or severe inflammatory damage.
• MRI shows soft tissue swelling around the hip joint, with possible fluid signals or abscess formation, and significantly thickened joint capsule, suggesting infectious or synovial inflammatory changes.
• Postoperative imaging shows that the femoral head and part of the femoral neck have been resected, indicating a “Girdlestone” postoperative appearance, leaving a large gap at the hip joint.
• The level of proximal femur resection can serve as a reference for classifying the type of Girdlestone procedure (Type I–IV), requiring correlation with the length of the remaining femoral neck.

II. Potential Diagnosis

Taking into account the patient's medical history (chronic hepatitis C, intravenous drug abuse, cirrhosis) and the recurrent presentation of hip infections or suspected infections, the following possibilities should be considered:

• Chronic suppurative arthritis or refractory infection: The medical history indicates repeated admissions for sepsis and suspected hip infections with limited improvement after treatment, supporting the possibility of a persistent or refractory joint infection.
• Femoral head necrosis or a secondary lesion from a prior infection: Long-term chronic inflammation or vascular compromise (e.g., alcoholic or acute vascular damage) may also lead to femoral head necrosis; however, infection remains the primary concern for this patient.
• Osteomyelitis (proximal femur): Commonly coexists with joint infections, particularly in patients with intravenous drug abuse and immunocompromise; osteomyelitis cannot be ruled out.

III. Final Diagnosis

Considering the patient’s persistent hip pain, history of infection, laboratory findings (despite negative preoperative joint fluid culture, there was a strong clinical suspicion of infection), and imaging evidence, the most likely diagnosis is:

• Right hip chronic infectious (septic or chronic suppurative) arthritis

Due to multiple comorbidities and the high risk of surgery or reinfection, the patient underwent a Girdlestone procedure as a “salvage” approach.

IV. Treatment Plan and Rehabilitation

Based on the patient’s condition and postoperative recovery requirements, the following treatment and rehabilitation recommendations are offered:

• Continue anti-infective therapy:
  • During the perioperative period and beyond, use appropriate antibiotics based on culture sensitivity or clinical judgment. Intravenous antibiotics may be necessary.
  • Monitor C-reactive protein (CRP), white blood cell count, and the local wound site closely after the operation to detect any signs of recurrent infection at an early stage.
• Postoperative rehabilitation and nursing:
  • In the early postoperative phase, strictly limit excessive weight-bearing. Under the physician’s or physical therapist’s guidance, perform bed-based range of motion exercises to support proper wound healing.
  • If partial weight-bearing is permitted, use a walker or crutches gradually transitioning to limited weight-bearing. If the resection is extensive (Type III or IV), pay particular attention to lower-limb alignment and load balance.
• Individualized exercise prescription (FITT-VP) example:
  • Frequency (F): Engage in 1–2 sessions of moderate rehabilitation exercises daily, such as bedside joint movement and quadriceps isometric contraction training.
  • Intensity (I): In the early postoperative period, maintain low intensity, paying attention to pain and swelling responses. If significant pain or redness occurs, reduce the training load and consult a doctor promptly.
  • Time (T): Each session should last about 10–15 minutes initially, gradually increasing to 20–30 minutes depending on the patient’s tolerance.
  • Type (T): Begin with mild exercises in bed or while seated; as rehabilitation progresses, include seated leg lifts, balance exercises, core training, and short-distance walking using crutches.
  • Progression (P): Gradually extend standing or walking duration based on pain and joint stability. If necessary, incorporate lower-limb strengthening exercises (e.g., straight leg raises or resistance band work) under the guidance of a physical therapist.
• Special considerations:
  • Due to the patient’s history of hepatitis and drug use, close monitoring of liver and kidney functions is essential, and medications harmful to these organs should be avoided.
  • Eliminating adverse habits (intravenous drug use, smoking, excessive alcohol consumption, etc.) is critical to prevent reinfection and support healing.