Frozen Hip Causes and Symptoms

The exact cause of frozen hip is unknown, and researchers have identified several potential contributing factors, including genetics, trauma, and underlying medical conditions.

The main symptoms and signs of frozen hip are hip pain and limited range of motion in the hip joint.

Frozen Hip Causes

Frozen hip can develop on its own, with no known cause (primary), or it may be caused by another underlying medical issue (secondary).

Primary frozen hip

Idiopathic – or primary frozen hip – occurs when a clear underlying cause of frozen hip cannot be identified.¹Joo YD, Sobti AS, Oh KJ. Measurement of Capsular Thickness in Magnetic Resonance Arthrography in Idiopathic Adhesive Capsulitis of Hip. Hip Pelvis. 2014;26(3):178-184. doi:10.5371/hp.2014.26.3.178 Researchers continue to investigate potential triggers, with some theories focusing on:

• Medical conditions: Certain health problems, such as diabetes and thyroid disorders, increase the risk, although the exact mechanisms remain unclear.
• Autoimmune dysfunction: An overactive immune system may mistakenly attack the hip joint’s capsule and synovial membrane, leading to inflammation and thickening.
• Hormonal imbalances: Fluctuations in hormone levels, particularly during pregnancy or menopause, might play a role in inflammation of the hip joint’s capsule.
• Genetic predisposition: Certain genetic or hereditary factors may increase the risk.

These theories offer potential explanations for why some individuals develop frozen hip without any apparent cause.

Secondary frozen hip

The inflammation and capsular thickening of the hip joint due to another medical problem is referred to as secondary frozen hip.¹Joo YD, Sobti AS, Oh KJ. Measurement of Capsular Thickness in Magnetic Resonance Arthrography in Idiopathic Adhesive Capsulitis of Hip. Hip Pelvis. 2014;26(3):178-184. doi:10.5371/hp.2014.26.3.178

Common secondary causes include:

• Hip surgery: Surgical procedures on the hip, such as hip replacement or repairs, potentially disrupt the joint capsule and surrounding tissues, leading to inflammation and scar tissue formation inside the joint.
• Hip trauma: Fractures, dislocations, or other injuries to the hip joint trigger inflammation of the synovial membrane and scar tissue formation inside the hip capsule.
• Hip conditions: Problems affecting the hip joint, such as labral tears, hip impingement (femoroacetabular impingement), and hip osteoarthritis repeatedly stress the joint capsule and synovial lining.
• Hip infections: Bacterial or viral infections within the hip joint, such as septic arthritis, cause inflammation and damage to the capsule.
• Repetitive microtrauma: Constant stress on the hip joint from activities like long-distance running or sports with forceful pivoting movements can lead to micro-tears and inflammation of the capsule.

Successful treatment requires addressing the underlying cause of secondary frozen hip. For example, diabetes or underlying hip impingement should be treated to prevent frozen hip complications and promote faster recovery.

Risk Factors

The following risk factors increase the possibility of frozen hip:

• Age. It is more common in middle-aged individuals between the ages of 40 and 55.²Chellamuthu G, Sathu S, Jeyaraman N, Jeyaraman M, Khanna M. Adhesive Capsulitis of Hip-A Systematic Review of Literature. Indian J Orthop. 2023;57(2):238-244. Published 2023 Jan 8. doi:10.1007/s43465-022-00808-z
• Sex. Women are more likely to develop it than men.²Chellamuthu G, Sathu S, Jeyaraman N, Jeyaraman M, Khanna M. Adhesive Capsulitis of Hip-A Systematic Review of Literature. Indian J Orthop. 2023;57(2):238-244. Published 2023 Jan 8. doi:10.1007/s43465-022-00808-z
• Medical conditions. Diabetes and thyroid disorders increase the risk of developing the condtion.²Chellamuthu G, Sathu S, Jeyaraman N, Jeyaraman M, Khanna M. Adhesive Capsulitis of Hip-A Systematic Review of Literature. Indian J Orthop. 2023;57(2):238-244. Published 2023 Jan 8. doi:10.1007/s43465-022-00808-z
• Genetic predisposition. The presence of specific genes or genetic variations is thought to increase the possibility of developing the condition.
• Previous hip surgery or trauma. Past injuries or surgeries increase the risk of damage to the hip capsule and surrounding tissues.

Reducing the risk of a frozen hip involves monitoring health conditions and treating underlying problems that increase the risk of this disorder; reducing inflammation in the body through a balanced, anti-inflammatory diet; and a healthy and active lifestyle.

Frozen Hip Symptoms and Signs

The symptoms start gradually³Alborno Y, Salameh M, Aboulebda M, Alam S, Ahmed G. Adhesive capsulitis of the hip joint in a young female. A case-report. Int J Surg Case Rep. 2020;75:526-529. doi:10.1016/j.ijscr.2020.08.008 and can affect one or both hip joints. The first symptom is hip pain, followed by hip stiffness. The degree of pain and stiffness varies depending on the progression of frozen hip.

The presence of other hip conditions such as hip labral tears or hip impingement causes additional symptoms to occur.

Early signs and symptoms of frozen hip

In the initial stages of frozen hip, the following symptoms are predominant:

• Hip pain. Mild to moderate hip joint pain that comes and goes and cannot be pinpointed to a specific location.
• Pain flare-ups with activity. Certain movements and activities involving the hip joints and legs cause the pain to increase, such as:
  • Sitting on the floor by bending the knees and crossing the ankles close to the body in the “tailor’s position”
  • Bending at the hips in a weight-bearing position, such as squatting
  • Rotating the hip out to the side, such as while getting out of a car
  • Bringing the knees to the chest
• Pain while lying down. Lying on the affected side causes the pain to flare up, and people often report experiencing hip pain while sleeping.
• Locked-up hip. The hip joint feels stiff, especially after long periods of inactivity, such as after driving, sitting at a desk, or lying down.

These symptoms typically last through the first few months. If left untreated, the symptoms tend to progress as the development of scar tissue causes the hip’s synovial membrane and capsule to become tighter and stiffer.

Progressive signs and symptoms of frozen hip

After the first few months, symptoms tend to include:

• Severe hip stiffness. The hip joints become increasingly stiff, making activities like climbing stairs or walking challenging.
• Reduction in pain. Over time, inflammation in the synovial membrane decreases, and the joint does not hurt during regular activities such as walking or climbing stairs. However, hip joint pain may flare up when the joint is bent or rotated excessively, such as while squatting.

These symptoms typically persist for up to two years, or more, and then gradually begin to resolve on their own, even without treatment.

Frozen Hip Diagnosis

The diagnostic process for frozen hip involves:

• Collecting a detailed medical history
• Checking the hip joint’s range of motion and specific movements that exacerbate pain
• Performing a focused musculoskeletal examination of the hip, nearby joints, and supporting structures, and a thorough nerve and blood vessel (neurovascular) examination to check sensation, strength, reflexes, and pulse
• Identifying or ruling out other conditions contributing to the patient’s symptoms

Frozen hip is a diagnosis of exclusion, meaning other potential causes are ruled out first before a confirmatory diagnosis is made.

Medical history and physical evaluation

The initial evaluation includes two areas of focus:

• Patient history: Specific questions are asked about:
  • Type of the symptoms, including when they started and what movements or activities make them flare up
  • Location and severity of the pain
  • Severity of the stiffness
  • Daily activities that are easy and difficult to perform
  • Information on past injuries and surgeries
  • Information on other medical problems, such as diabetes or thyroid disorders
  • Family history of frozen hip
• Physical examination: The doctor evaluates:
  • The hip joint’s range of motion and strength of muscles controlling the hip joint
  • Swelling and/or redness near the hip
  • The surrounding/adjacent joints, such as the sacroiliac (SI) joint, lumbar spine (lower back), knees, ankles, and feet

These steps provide valuable clues in the diagnosis. For example, symptoms that are indicative of frozen hip include:

• A gradual increase in generalized hip pain over weeks or months
• Significant stiffness and limitations in movement that have progressed over time

Further evaluation involves performing one or more diagnostic tests.

Diagnostic tests for frozen hip

Minimally invasive injections and surgical procedures are generally more useful than imaging tests for diagnosing frozen hip.⁴de Sa D, Phillips M, Catapano M, et al. Adhesive capsulitis of the hip: a review addressing diagnosis, treatment and outcomes. J Hip Preserv Surg. 2015;3(1):43-55. Published 2015 Nov 27. doi:10.1093/jhps/hnv075

Imaging tests are used to rule out other hip conditions and support the diagnosis, especially because other hip problems, such as a hip labral tear or hip impingement, can co-occur with frozen hip.

Two specific diagnostic procedures that can be considered are:

• Diagnostic intra-articular contrast injections, in which the hip joint capsule is injected with a contrast agent, and its flow is monitored on a computer screen. This type of diagnostic injection is also called arthrography.
  In frozen hip, the capsule surrounding the hip joint shrinks, reducing the available space for the fluid to disperse compared to a normal hip joint. A joint capacity below 12 ml usually confirms the diagnosis.⁵Joassin R, Vandemeulebroucke M, Nisolle JF, Hanson P, Deltombe T. Adhesive capsulitis of the hip: Concerning three case reports. Annales de Réadaptation et de Médecine Physique. 2008;51(4):308-314. Doi:https://doi.org/10.1016/j.annrmp.2008.03.008
• Arthroscopic hip surgery, a minimally invasive surgery that both diagnoses and treats frozen hip in the same procedure. The surgery involves 2 or 3 small incisions, about 5 mm each, near the hip joint.   
  • Arthroscopy procedure: A pencil-sized tool called an arthroscope, equipped with a tiny camera, is inserted through one of the incisions and guided near the hip joint using fluoroscopy or live x-ray. The camera displays the view around the joint on a computer screen for the doctor to confirm frozen hip and/or other problems affecting the joint.

The other incisions are used to insert diagnostic and/or treatment instruments.

• Possible treatment: If a frozen hip or other contributing hip problem is identified, the doctor treats the hip capsule and the surrounding structures in the same procedure.

Arthroscopic surgery typically involves general anesthesia and is reserved for cases where frozen hip is strongly suspected.

Tests to rule out co-occurring conditions contributing to frozen hip

In some cases, x-rays, magnetic resonance imaging (MRI), or computed tomography (CT) scans are ordered to identify or rule out conditions contributing to frozen hip, such as hip impingement, fractures, and degenerative changes.

Blood work is ordered to check inflammatory markers (C-reactive protein and erythrocyte sedimentation rate) and hormone levels, as these markers help diagnose medical conditions such as hip osteoarthritis, chronic inflammation, diabetes, or thyroid disorders, which may be contributing to frozen hip.