Orthopedic Teaching Cases 2023, Jan, 20 | 12:00 am

CASE 45 compartment syndrome

A 26-year-old man involved in a high-speed motor vehicle collision arrives to the emergency department with an obvious deformity of the right leg. Orthogonal radiographs of the right tibia/fibula are depicted in Figure 6–47A and B. An initial

assessment deems the patient to be stable with no evidence of associated intrathoracic or intra-abdominal injuries. The skin is intact, there are palpable pulses distally, soft compartments, and the patient is deemed suitable for operative treatment.

 

 

 

Figure 6–47 A–B

 

All of the following are contained within the deep posterior compartment of the leg EXCEPT:

  1. Tibialis posterior

  2. Flexor digitorum longus

  3. Plantaris

  4. Flexor hallucis longus

 

Discussion

The correct answer is (C). All of the above are contained within the deep posterior compartment of the leg except for plantaris, which lies in the superficial posterior compartment. Additionally, the posterial tibial vessels and nerve lie within the deep posterior compartment. The superficial posterior compartment also contains the gastrocnemius and soleus. The anterior compartment contains the anterior tibial artery, deep peroneal nerve, tibialis anterior, extensor hallucis longus, and the extensor digitorum communis with accompanying peroneus tertius. The lateral compartment contains the superficial peroneal nerve, peroneus brevis, and peroneus longus.

The patient is indicated for intramedullary nailing of this closed fracture. The

patient is positioned supine with the knee in a flexed position, and a medial parapatellar approach is used.

Which of the following statements regarding the operative management of this injury is false?

  1. The starting guide wire is placed in line with the medial aspect of the lateral tibial spine on the AP radiograph, and just below the articular margin on the lateral view.

  2. The use of a thigh tourniquet during reaming does not appear to increase the risk of thermal necrosis within the tibia.

  3. There is no benefit to reamed versus unreamed intramedullary nailing of closed tibia fractures.

  4. Anterior knee pain following intramedullary nailing of the tibia can be expected in up to 50% to 75% of patients.

Discussion

The correct answer is (C). In a large, prospective, randomized clinical trial, the SPRINT study demonstrated a benefit for reamed intramedullary nailing of closed tibia fractures. This same benefit was not shown for open fractures. Choice A accurately describes the optimal starting point for intramedullary nailing of tibia fractures. The generation of heat during reaming has been shown to be a function of reamer size and isthmus diameter more so than whether or not a tourniquet is used. Anterior knee pain is a common patient complaint (more than 70% of respondents in one series) following reamed intramedullary nailing of the tibia with the knee in the flexed position.

The patient undergoes successful intramedullary nailing and is transferred to the medical surgical floor. Six hours postoperatively, the patient begins to complain of progressively worsening anterior leg pain that is exacerbated by ankle motion. Palpable pulses are present distally. The patient’s blood pressure is measured to be 107/66 mm Hg.

Which statement accurately describes the appropriate evaluation of the patient’s condition?

  1. As the patient’s fracture has been definitively stabilized, the knee should be flexed and the leg elevated.

  2. In order to completely evaluate the extent of underlying intracompartmental pressures, it is advisable to measure compartment pressures as remote from the original fracture as possible.

  3. An intracompartmental pressure measured to be 25 mm Hg is an indication for urgent fasciotomies.

  4. The presence of palpable pulses does not rule out the possibility of an evolving compartment syndrome.

Discussion

The correct answer is (D). Although the patient’s pulses are palpable distally, this finding alone should not be used to rule out compartment syndrome. The fact that a tibia fracture has been stabilized definitively with an intramedullary implant does not preclude the possibility of compartment syndrome postoperatively. Compartment syndrome remains a clinical diagnosis and the presence of increased pain with passive stretch of the toes/ankles raises the clinical suspicion. Compartment pressures can be measured to provide additional information. When measuring compartment pressures, the pressure should be checked within 5 cm of the fracture. The decision to perform fasciotomies for treatment of compartment syndrome is based upon the difference (ΔP) between the diastolic pressure and the measured compartment pressure rather than an absolute measured compartment pressure. A ΔP value of 30 mm Hg or less warrants fasciotomies.

When assessing the adequacy of reduction of a tibia fracture, all of the following are considered acceptable parameters EXCEPT:

  1. Less than 1 cm shortening

  2. Less than 10 degrees of sagittal plane deformity

  3. Less than 20 degrees of internal rotation

  4. Less than 5 degrees of coronal plane deformity

 

Discussion

The correct answer is (C). All of the answer choices correctly describe appropriate parameters for alignment of the tibia with the exception of 20 degrees of internal rotation. No more than 10 degrees of rotational alignment is considered acceptable for tibia fractures.

Objectives: Did you learn...?

 

The anatomy of the compartments of the leg?

 

The appropriate guide wire start point for intramedullary nailing of the tibia with the knee flexed?

 

The common deformity encountered in fractures of the proximal tibia?

 

Incidence of anterior knee pain following intramedullary nailing of the tibia with the knee flexed?

 

The diagnosis and management of compartment syndrome in the setting of closed tibia fracture?