Hong kong and modified hong kong procedure

Aim of these procedures is to surgically augment chemotherapeutic treatment by addressing issues such as

It involves either a thoracotomy, thoracoabdominal, or lumbar retroperitoneal approach, depending on the spinal level involved.

Major vessels are mobilised away from the operative field after the division of intercostal or lumbar vessels.

The vertebral column is cleared on both sides of the vertebral bodies.
All dead and necrotic material, along with adjacent discs, are removed until healthy end plates of adjacent vertebral bodies are exposed.

If the patient has a neurological deficit, the posterior longitudinal ligament is divided, and any pseudomembrane compressing the dura (the membrane covering the spinal cord) is removed to adequately decompress the cord or cauda equina.
If there is no neurological deficit, the posterior longitudinal ligament is left intact.

A graft is harvested from either 2-3 pieces of ribs tied together with suture or a tricortical iliac crest bone graft. The use of rib graft is well-documented and was successfully used in almost all cases in the study.
The recipient site (the space where the diseased vertebrae were removed) is further opened up by manual pressure on the posterior elements, and a kidney bridge (a surgical table attachment) is raised to expand the space even more.
The graft is then inserted tightly between the healthy end plates.
Posterior pressure is relieved, and the kidney bridge is lowered to further securely fix the graft in place.

The pleura (if a thoracic approach was used) is closed over the operated level. A drain (chest tube or retroperitoneal drain) is placed, and the wound is closed in layers.

This operation is exactly similar to the Classical Hong Kong Operation described above, with one solitary inclusion: instrumentation.

Instrumentation: In the study, this involved the use of lateral single body screws fixed with a rod or 4.5mm AO titanium broad DCP and 6.5 mm AO screws. The purpose of instrumentation in MHK is to give support to the graft until it forms a stable union with healthy vertebrae.

Historically, early intervention with stabilisation was avoided due to the fear of secondary infection; however, studies have confirmed that mycobacteria adhere poorly to metallic implants compared to other bacteria. Titanium cages with grafts are now successfully used.

Patients undergoing either operation are given four-drug first-line anti-tuberculosis therapy (Rifampicin, Isoniazid, Ethambutol, Pyrazinamide) with optional Levofloxacin and Amikacin for an initial two months.
This is followed by a three-drug regimen for another ten months.
During this period, regular ESR levels and serum ALT levels are monitored.

Patients are mobilised out of bed by trained physiotherapists.
They are started with breathing exercises.
Rehabilitation is conducted at the Armed Forces Institute of Rehabilitation Medicine, Rawalpindi, for a minimum period of two weeks.
Before walking, a Boston brace or hyperextension brace is advised, which is discarded after clinical and radiological evidence of union.

Patients are advised monthly follow-up for the first three months, then two-monthly visits until ATT completion. Thereafter, they visit the outpatient department every six months.
Improvement is assessed by radiology and clinical examination.
X-rays of the spine are carried out on each visit, with kyphosis angles measured by Cobb's method. Dynamic lateral flexion/extension X-rays are taken at 6 and 9 months post-operatively to check for union.
Neurological improvement in sensory and motor power is seen by the American Spinal Injury Association (ASIA) score.
Pain is assessed by a graphic rating scale (GRS).
Patient satisfaction is also graded.